relative newbie here.

I was upgrading a light fixture and at the same time installing a dimmer switch. I accidentally purchased a 3-way switch instead of the required 2-way switch and my "helper" removed the "insulating sticker" that covers the pole used for the 3-way switch and I didn't notice.

I installed it, flipped the breaker back on and went to test out the light. When I did, I could almost immediately smell a faint burning smell (really bad smell). I went back, turned off the breaker, and pulled the switch back out. The extra pole had come in contact with the box.

I took it out, replaced the "insulating sticker" and screwed the pole in so it isn't sticking out.

Some questions.

  1. Is what I've done safe?
  2. Is that insulating sticker really the protection against something bad?
  3. Shouldn't the breaker have tripped if a "hot" pole came in contact with the grounded box?
  4. My wife can still smell the foul smell - does that smell linger or do I have a bigger problem?


  • Does the dimmer still work? Commented Mar 13, 2017 at 0:25
  • Switch works, dimmer doesn't.
    – user12529
    Commented Mar 13, 2017 at 0:58
  • 2: No, code requires that it be a wire nut. 4: Whether or not it still works, yes, you have a bigger problem ;)
    – Mazura
    Commented Mar 14, 2017 at 1:43

2 Answers 2


You killed it, man!

The solid-state switching devices in dimmers tend to fry when the dimmer's output is shorted. Replace the dimmer, and this time, don't peel the insulating sticker off to avoid another short. The breaker may have tripped eventually, or it may not have; the good news is that what you did is OK for now as the smell is simply lingering as odors are wont to do.


If "the smoke is released" from anything electronic, that means something is burned.

Some component got either destroyed or overheated to a point where it is unreliable and might fail (maybe catastrophically) at any time in the future.

It is also possible that a component got destroyed that is NOT necessary for the whole assembly appearing functional - but that IS necessary for making another component not failing within hours or months from overload, OR that is necessary for keeping another possible component failure safe (as in, the whole thing will not burn or explode!). So "but it still works" is irrelevant.

Most things that burn with a stink do so releasing carbon - literal carbon that can get lodged anywhere inside the assembly, which is not a concern about "carbon footprint", but about the short circuits or degraded behaviour of insulation this conductive material can cause now or later.

Overheated/failing insulation turning into conductive material, causing more shorts and heating, creating more conductive material ... this is known to have crashed airplanes.

So: Even if it appears to work, it is unsafe and completely unsuitable to be connected to a potent power source (as the mains is) unattended.

  • Ok - that makes sense. I guess the follow-up question is what do I do now? Kill the breaker, open up the walls to check the wires?
    – user12529
    Commented Mar 14, 2017 at 2:03
  • I suppose it might make more sense to bring in a professional at this point :)
    – user12529
    Commented Mar 14, 2017 at 3:00

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