I have a built-in barbeque (Braai if you're from South Africa!), which is basically a big steel box with brickwork all around. There is a normal electric incandescent light bulb on the inside and I was surprised to find a few weeks ago that this had started to leak current into the barbeque itself.
After removing some of the brickwork, I could see no obvious problem with the wire insulation at all. This leads me to believe that the problem is moisture getting in-between the steel casing and the brickwork, flowing down the wire and accumulating within the fitting for the light bulb. This seems rather unlikely, but I don't really see another way.
Normally, I would then simply use some form of silicone or similar insulator and cover the base of the fitting, but since this is a barbeque, it tends to get a little hot. What is the best kind of insulator to use in this case?
Best Answer
What does the manufacturer say ...
I suspect the roof seal doesn't get too hot in normal use. You can get "heat-resistant silicone" intended for use with flues etc.
Personally, I'd get the metalwork properly earthed (grounded) to help avoid killing family or guests.
That is possible, inspection of the fitting may make this clear
As Ed Beal pointed out, soot is largely carbon and carbon is conductive. Maybe soot is getting somewhere it shouldn't.
I would examine the light fitting and its connections very carefully to try to identify what is creating a conductive path from the hot (live) wire to the metal frame.