I can’t say I’ve been in a shady job myself (at least anything beyond the normal corporate shadiness). But I’m wondering if anyone here has ever worked in a shady place - like a boileroom-situation, where it’s you, a desk and a phone and little else, or some place where you have only a vague idea of what’s going on and fear you may not get a paycheck at the end of the week. Or maybe you’ve been in a job where you see Tony Soprano-types walking in and out all day.
Well, not shady in quite the sense you mean, but I did work as a canvasser for America Coming Together. We got fined the better part of a million bucks by the Federal Elections Commission! (And here you thought the FEC was toothless …) http://www.fec.gov/press/press2007/20070829act.shtml
For a little while in college, I was a telemarketer selling aluminum siding. Nothing illegal or anything, but it’s not one of the better loved professions. (I ended up getting fired for not selling any in the month I was there.)
At the age of 14, I worked with underage children/teenagers ranging from 12-16 to help clean a now demolished motor speedway in Louisville. Basically, a local cleaning company was tasked with cleaning up all of the trash on the weekends and decided they’d pay anybody that decided to show up and work. Now, granted, the biggest safety risk was a bad sunburn, but it stills seems kind of skeevy to pay 12 year old strangers under the table to help with a fairly major contracted job. But, hey, the pay was good - $25 under the table for three hours of work isn’t too shabby for someone that’s not even old enough to make minimume wage at McDonals. I was a faithful customer of the ice cream man that summer.
Edit: Let it be known that speedway was not demolished until years after I had worked there. We’re talking trashbags and rakes, not bulldozers and dumptrucks.
I’ve worked in several restaurant kitchens. We had more felons than many prisons, more weapons than an Army platoon, and managers snorting coke and committing statutory rape in the office.
I will never, ever let a hypothetical child of mine work in a kitchen.
Stranger
I was hired by a night watchman (they found me on the street more or less) to proof an English language newspaper on-the-spot in a former Soviet Republic. The regular editor was sick or out of the country - can’t recall. I had the final say as to what went to press that night since he was dropping it at the printer on the way home (at 1 in the morning).
I was paid in cash and the front page was a big story about some sort of trade negotiations between the country I was in and a neighboring country. One of the quotes was from the country’s president and it was not clear what he was trying to say so I was told to “make something up”.
I probably could have started a war… I made sure my name was not on the issue and collected my cash. 
I’ve been a timeshare salesman, a Kirby salesman, Casino Dealer and restaurant club telemarketer…
I collected money for parking in downtown St. Louis over the 4th of July. We weren’t in a bad area, but we were selling parking spaces for $20 apiece down by the riverfront. The guy we were working for, let’s call him Eddie, because he was an Eddie kind of guy, was out of his head on booze and god only knows what else, cruising around in a pimp-mobile and stopping by every once in a while to collect the money and getting more and more fucked up as the day went on.
I’m not entirely sure that what we were doing was legal, though. We were down the way a bit from the main festivities, and we may have been charging for parking that was technically free. About an hour before the fireworks started, the cops stopped by and asked us if we had permits. We gave them Eddie’s pager number, but by this time Eddie wasn’t answering pages. The cops bugged off and we kept selling parking spots to more and more irate people until about 10 minutes before the show, when some dude started screaming that we were gouging for parking. We just gave up at that point and let him park, climbed onto the roof of a car and watched the fireworks.
I worked for a guy once who was from India and had a business plan of selling textbooks printed there to North American students for cheap. Despite the substantial initial cost of shipping a few big crates of textbooks here from India, the textbooks there cost so much less that it was still profitable to resell them.
Apparently textbook publishers make differently priced copies for different regions. These textbooks were exactly the same as the versions made for the U.S., except they had these big labels printed on the front that said “For sale only in India and Pakistan”. I asked him about it and he said there is some sort of legal loophole that makes it O.K. to sell these in the U.S. despite that label, and sent me a link to something on Yahoo! Answers explaining it. The response was actually very detailed and I couldn’t quite grasp all the legal ins and outs but I just trusted that if someone was going to get sued it would be him and not me. But I still felt really paranoid about being implicated, especially when eBay suspended the account we were using to sell them on there for violation of terms. (he set up accounts with at least 8-10 bookselling sites besides eBay)
The workplace situation was very much like the OP describes, since I was the only employee of the business and just worked out of the back of his house.
An umbrella salesman.
Ba-dum-BOOM!
I’ll be here all week, folks.
I worked for a man selling marble tile. I worked as receptionist and payroll bookeeper. I now know he was shady because I carefully took out witholdings for each of the other two employees, as well as for myself. He never paid them, he just pocketed the money. We all had my notes showing that we had the witholdings taken out of our pay, however he had left the country by they time we filed our taxes.
When I was but a callow youth (and a cretin), I did six months (!) of highly exploitative office management on a paperboy’s salary in Miles Platting, Manchester (where I saw my first police forensic cordon and corpse tent. Bucolic, no?).
The core value of the business was misleading the vulnerable out of their old mobile phones using cold-calling and misuse of the EU WEEE (really) Directive.
The management were an appalling double team comprising a floridly unpleasant ex-publican binge drinker and sex pest who’d been hit in the face so many times that his tear ducts now malfunctioned and dribbled, constantly, and a nasty little man called Steve who I hope has been broken extensively by life in some elaborate expression of natural cosmic justice.
Wages were cash, no payslip (Yes, I was a cretin). National Insurance contributions? Good joke! There is no record of me ever having worked there, the manager was just skimming £20 in beer money off my wages each week. I was pleased to see them go out of business the month after I walked out at speed after he tried to pay me for sex.
I spent a summer driving around, picking up checks for a “firefighter’s charity”. They worked out of a basement office, didn’t pay me much, and the whole thing seemed a little off. I did get to learn a lot about my neighboring towns, and where everything was, so that was nice.
I worked for a screen-printing company, very tiny, only like 4 employees, including the owner. There were weers that my paycheck would bounce, and it got so bad my bank would not accept them. The final straw came for me when I went to a grocery store to cash the check and when it bounced, they had my checking account frozen. I quit the next day.
The other kind of shady- I worked as a telemarketer for a company that solicited for donations for various charities. It sounds worth-while, but the charities got no more than 12% of the money collected, and normally only 3-5%. I felt like I was robbing old ladies of their social security checks.
Not me but my Mum. Her first job, at the age of 15 in 1940’s Britain, was office junior. There were two bosses, a secretary and her. She was basically a dogsbody, making the tea and conveying numerous parcels to the post office. One day, after a few months, she was the only person to arrive at work --apart from sundry policemen who had lots of questions she couldn’t answer. She found out that the secretary was in as deep as the bosses and having an affair with one of them but she never did discover what was in those parcels.
I worked with a repo man helping repossess cars and trucks. Besides bank repos, he would occasionally tow off high end cars and instead of delivering them to the storage lot, he would take them to a buddy of his. Can you spell chop shop? The pay was pretty good but I decided it wasn’t worth going to jail over.
In college I worked briefly for a very small ISP. My job was to call people who hadn’t paid their bills, and beg them to pay. This ISP was notorious for slow and frequently interrupted service, and most of the people I called had stopped paying because they were trying to cancel their accounts. If you called the ISP, you got a phone tree that gave you a certain number to press to cancel your account. This number dumped you into a voicemail which was never ever checked.
I worked evenings and weekends, and there was only one person in the office besides me. A “tech support” guy. If I called someone who wasn’t paying because of bad service, I assured them that I could transfer them to “tech support” right away, and they would get their problems fixed tonight. But they had to make a payment over the phone to get their account current before I could do that. After they payed, I transferred them to “tech support” guy, who gave them reasons why the problem was with their own equipment, and they would need to get a better computer and/or modem and/or wiring to fix their problems with their service. He had a list of plausible sounding reasons why the person’s own equipment would cause service to be intermittent and slow, and would just pick one at random.
I didn’t get any hourly pay whatsoever. I got paid based on how many people I got to pay their bill. No benefits.
I think I lasted 2 days, maybe 3.
I worked for about three weeks for a futon factory, cutting fabric. The cutting room was in the same office as the retail showroom and sales office in an interesting old brick building, lots of light. They bought up odd lots of cotton canvas – roll ends, rolls that had machine grease on one end, things like that. We cut as many futon-sized pieces as we could get from it all; basically recycling stuff that would otherwise get landfilled, which was fine by me.
What was not fine by me was that they made claims about the quality and durability of this fabric that were false – something like saying it was “top quality 12 oz canvas” when the lots contained some 12 oz but mostly 10 and 8 oz. They also said they guaranteed their futons. This meant that the showroom dealt with lots of customer complaints, which we overheard the salespeople handling. “It split up the middle the first time we slept on it!” Standard reply: “Gosh, you must have used it in a way other than was intended.” Right.
I worked for what was then called the Wilhelmina Scouting Network for about a month - formerly known as Transcontinental Talent, WSN, TCT, and the Web Style Network.
It was the scam that Lou Perlman was originally arrested for (although not the one he was convicted of running) - basically, it was a call center in Orlando which fooled people into forking out $1000 for the privilege of having their pictures available to “more than 1,000” casting directors, modeling scouts and other talent finders. In reality, there were maybe 10 or 20 companies using the service. I worked overnight- they used to run ads during late-night programming (1-800-MODELING). After the first week or two, pretty much everyone figured out that the whole thing was a scam; all the company’s upper management except Lou had profiles on the Florida Department of Law Enforcement search engine- bad checks, mail fraud, credit card fraud, you name it.
The overnight staff (like me) mostly spent our evenings watching bootlegged movies, throwing paper aeroplanes, surfing the web and having sex. My (only) two fond memories of the place are finding the Straight Dope via bored.com when I was working there, and a very flexible lifeguard named Amber who I would meet in the broom closet every night.
ETA: I got laid off after a month - turned out the overnight staff weren’t very profitable. 
Well, as per a previous thread, I worked for a few years as a phone sex operator. Not too shady, I don’t think, since I gotta believe that most of the guys I talked to knew I wasn’t really 22YO, blond and busty and into any old kind of kink that got them off.
In fact, once my FIL remarked he was glad I was doing phone sex, not a psychic hot line, because at least with the phone sex, the customer gets something for his money!