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!
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.