Thought I should mention this in case it helps someone else avoid injury. Also curious about whether the wiring on a switchbox in my home has been botched or not.
I was installing a new GE light switch yesterday, and did the normal process to go out and turn off the breaker for the circuit that includes that switchbox. Then I returned to the switch box and verified via trying each switch repeatedly that the power was out.
Removed switch cover, removed the switch I was replacing, and started to install the new switch. Was part-way through when suddenly I got a huge shock. Totally freaked me out. I don’t remember exactly which wires were connected at that point to the new switch (should probably have written that down.)
I immediately stepped away and went out to the panel to confirm I had really turned off the correct circuit. I confirmed it was off (and as noted the lights weren’t working after I had switched it off). However, I noticed another switch directly below the one I turned off had been tripped. Huh? I turned it on again and returned to the switch box w/my trusty voltage tester, and sure enough, with the second circuit switch on again the black wire to the switch I was installing was hot, the other black wires in the box were not. I turned off the second circuit as well and the rest of the installation went normally.
So it appears that the switch box I was working in was wired to two different circuits/switches in my panel, and the labeling that the electrician had done when he installed my new panel some years ago did not communicate that at all. (I had actually reconfirmed the labeling a few years back, but since the lights didn’t work when that switch was out, it looked OK at the time.)
The second switch that tripped when I got shocked was labeled as controlling power for another area in the family room. It does control that, but somehow is also tied into the switch box for the light switches I was working on as well.
I’m no electrician, but it seems like this is probably not compliant with code, and even if it is it is very dangerous if not carefully labeled.
And after the fact I realized I had broken my own safety rule when working on electrical stuff - always re-confirm w/tester that the wires I’m working on are all dead. So that’s on me.
But I’m unhappy w/this odd setup my electrician left me with, and wondering if other electricians here can confirm if this setup is as bad as I think it is, or if it’s uncommon but sometimes done, and the main issue is the lack of correct labeling on the panel.
So learn from my mistake and never assume lights not working means no power to the box.
And thanks for any feedback.