I explained to my flying instructor once how Lucas Electrics worked, and laughed his arse off. He is an electrical engineer.
All that is said is true about the electricity being conducted by smoke. For a few years I would occasionally get the odd puff of smoke would come out of my indicator switch, when indicating a right turn. Then one day lots of smoke came out, then the smoked stopped and my indicators no longer worked. I installed a new switch, which was completely filled with smoke I would assume, and then I had indicators again.
James.