davidm, it sounds like that house had the switches on the neutral end, instead of on the hot end like they should be. Ironically, in such a case you’d be less likely to get a shock with the light turned on (though of course then you might burn your fingers on the bulb).
No help. But I feel your pain. I’m no slouch when it comes to remodeling. I put a two story addition on my house. I designed and built it. That included moving the mech room and infloor heat and laundry as well as moving the elec meter and digging up the incoming 220v.
Now I’m having an entry way replaced by a trusted contractor. The entry way is not on the original house plans. And is fed by three circuts that feed the odd outlet in the rest of the house. GAH.
A quick way to find out what the hell is hooked up to what is to turn on every dam light and appliance and then start throwing breakers and testing stuff. You will want a tester for the odd outlet.
I have a breaker tester. Works great.
For those that say back away, I understand why you said that, but I’m not a complete novice, I’ve replaced both switches and sockets and installed new 3-way switches. And I did note the wires and put them back. Problem (I think) was a combination of old switches (no common label) and a Frankenstein of a wiring job. Out of 6 wires, I had 5 different colors (3 different blacks, 1 common red, and 1 ‘white’). The previous guy had the hot for two different lights all wired up together and that was throwing me as well. Either way, wired up now, works great and thanks for all the help. For folks like me, I really do recommend K2500’s method as it seems to be foolproof and might help you straighten out one of those ‘oddball’ wiring jobs. And you get to use that multi-tester you bought! 
Oh, this thread is about electricity. Never mind! 
A DPDT wouldn’t need cross-wiring to function as a threeway. What’s a train layout?
A train layout is a bunch of tracks (and usually some background scenery, but that’s not relevant here) hooked up for a model train.
What if you’re pulling power from the track for the lighting on the scenery? 
Ah! I failed to keep it simple and had assumed it was a particular variety of control layout. I dreamt of schematics all night.