Neither would I but (all together now) I just work here, boss.
All of this is to the side of what I care(d) about: making sure I can do what I’ve been told to do without destroying something. Whether there are alternatives to that task is immaterial.
To you, yes. But others reading this thread with a similar situation might benefit from the alternatives mentioned here.
How so? It’s unconventional, yes, and somewhat counter-intuitive, but unless I’m missing something it’s just as safe as having the switch wired properly. That is, there’s no fault that I can think of which could arise with both wires under one terminal that couldn’t also occur with the same likelihood as with the wires correctly installed. That, provided the wires are secure under the terminal screw.
Electrically, it’s the same as a closed switch.
I wondered the same thing (why would it not be safe). The ONLY think I can think of is that (if the switch is on), the ‘unused’ terminal will be hot. But, when working with electricity, you really shouldn’t go around touching terminals, used or not, unless you’ve tested them.
How about “Touch this switch and you are fired”?
Didn’t read far enough… :smack:
Of course.
BS, Electronic Engineering Technology
MS, Electronics and INstrumentation.
Go with the wire nut and blank plate.
Besides which the unused terminal will be behind the faceplate…
There’s the rub, isn’t it? The terminal screw is designed to secure one wire, and create a proper connection between that one wire and the switch/outlet. It is not designed to secure two wires to each other, and create a proper electrical connection between those two wires. You run a much higher risk of having that connection fail than you do with a wire nut. A failed connection will cause the outlet to fail, or may just create a hot spot and start a fire.
Cheesesteak
Guess I’ve been away from this board for a while but you answered Q.E.D.'s question quite well.
From what I’ve read, a screw terminal is only used to secure one wire - that’s it.
My suggestion about using a back wire connection with its associated screw terminal
is much safer and secure but I bet it is not approved in the National Electrical Code.
And it sure is an extreme cheapskate solution because a wire nut would do the job.
Wolf_Meister and Cheesesteak, it is an extremely common practice to place two wires under a single screw terminal on light switches because the circuit doesn’t always end at the switch. The hot wire will run to the switch and then continue on to the next switch or plug in the circuit, so safety is not really an issue.
I suggested this alternative as one that “didn’t require a trip to the hardware store”. I would generally use a wire nut and a blank in this situation myself, but might go with the alternative if I thought I might rearrange the furniture some day and have need of a switched outlet in that place again. It would be much easier to reconnect it if the switch was already there. Also, esthetically, I’m not fond of blank plates on walls. It looks like a mistake being covered up, whereas a switch, even non-functioning, looks normal to me.
I note that Mathochist has already procurd a blank plate and a wire nut, so he shouldn’t have any problems removing this switch. I will assume he’s savvy enough to kill the circuit before working on it and has the proper sized wire nut for this application. Probably a yellow, but if there are two wires on the hot terminal already, he might need a red. Of course, if he has the misfortune to encounter aluminum wiring, all bets are off.
Incidentally, the little plastic wire-twisting-together thingy is a “splice cover”.
If you end up doing something weird, I’d suggest writing a small note explaining your decision and tucking it in the box. In addition to not confusing yourself if you go back to make modifications ten years later, you can people it’s a teeny-tiny time capsule.
Safety is always an issue. Is that an accepted method under the NEC? Because, frankly, I don’t care whether or not it’s “common”, I care whether or not it is up to code. Code violating setups are already way too common, my house came with at least 4. Let’s not go out of our way to suggest another one. In your described situation, isn’t that what pigtails are for?
I did a bit of research and dug up this from the state of Washington (warning .pdf)
Unless the switch is labeled as accepting 2 wires under the screw, putting 2 wires under the screw violates the NEC. I don’t have any switches handy, but my box of outlets clearly shows one wire in the diagram, and accepts up to 10ga on the side terminals and 14ga in the quick connect. Using the quick connect, as wolf_meister mentioned, would probably violate 110-3b, since the switch wouldn’t be used in accordance with the instructions.
If being up to code is going to cost thousands of dollars you don’t have, I wouldn’t mind coming up with creative solutions. When the correct fix costs 10 cents what’s the motivation for creativity, outside of sheer laziness?
Cheesesteak, today I learned a new thing. After reading your post I called my brother (a Master Electrician). He tells me that only switches and plugs which are UL listed for multiple conductors may have two wires under one terminal. The only ones he knows of use a pressure plate, where the wires are under the pressure plate, which is tightened by the screw. In all other cases a pigtail must be used.
Thank you for correcting me on this.
As a side note, even though it is approved by NEC, I would not normally use the quick-connect. It has a bad habit of failing after 10-15 years of use and killing a whole string of switches or plugs.
rhubarb
Yes, I always use the screw terminals as opposed to those back wire (“quick connect”) plug-ins. As you said, they are unreliable and can fail.
Cheesesteak
I had a feeling my “cheapskate” solution would not be in compliance with the electrical code - now I’m sure. But hey it saves the ¢ost of one wire nut. 
(This message Approved by the Penny Wise Dollar Foolish Electrical Association).
The other basic problem with the cheapskate idea is that it leaves a switch related to an “on” socket which may look as if it will turn that socket off but which will not. Yes, I know that it would be silly for someone to turn off the switch and then assume that the associated socket was dead. People do silly things. Better not to help them.
And while we are on good wiring practices, it is a good idea to wrap around the switch (covering both terminals) with electrician’s tape. I have rarely seen it done and it is not required by any code I have seen, but it helps prevent shorts due to the bare ground coming into contact with a live wire.
I have seen it done occasionally. What really burns my bacon is an apparently common practice among electricians. They use the stab-in connection (quick-connect) on the back and leave the side terminal screws fully extended (normal out-of-the-box condition). This is not too bad in residential caonstruction where the switch/plug boxes are plastic, but in commercial construction, with metal boxes, a loose device can make a very startling light show when the screws touch the side of the box.
Yikes, I had always thought the stab-in connections were a cheap and somewhat dangerous way of doing things. Some of them hold very poorly even when new.