Last night I started smelling what seemed to be burning plastic. Simultaneously I noticed that an overhead light was flickering sporadically even with the power turned off. I went to the switch and found two simple switches. the hot wire comes into a other light switch and is then chained to the light switch in question. After unhooking the hot wire completely from the switch the light was still found to be flickering intermittently. Of note the light was only turning on some of the time when the connection was made at the switch. I currently have the power turned off at the breaker and awaiting guidance!

  • The only time I have come across a hot wire is when the wire was not firmly screwed into the connector
    – Dirk Bruere
    Commented Oct 23, 2019 at 12:47
  • 1
    Are you sure you have the correct hot wire? Almost sounds like a switch leg that shorted in the fixture , I have seen this before the damage was caused from an oversized lightbulb created two much heat and melted some insulation. I would be checking in the light fixture for damaged insulation.
    – Ed Beal
    Commented Oct 23, 2019 at 13:07
  • Make sure you've got the right switch since you've got two there.
    – JACK
    Commented Oct 23, 2019 at 14:40
  • It is possible that the original installer screwed up and put the switch on the return side of the light fixture, leaving the fixture "hot" , in which case any leakage path to ground would allow the light to flicker. Commented Oct 23, 2019 at 17:41
  • Is that light LED, fluorescent/CFL, or incandescent? Is power run to the switch first, or to the light first? Where are you on this planet? Commented Oct 23, 2019 at 23:57

1 Answer 1


This is serious business. This is a parallel arcing fault, meaning it is not arcing across a gap, but arcing between a hot conductor and an appliance conductor, effectively bypassing the switch.

I would expect to see/feel the damaged area, because it will be warm to the touch.

It is a hazardous situation because it is quite likely to start a fire. To avoid these, try using an AFCI breaker in the panel.

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