OOPS! Sorry!
My old boss used to work for his boss and back then, they used to drill all their holes using a brace and bit! Everything was armor cable, no RX and the outside wire was lead sheathed.
However staying on thread, I am still hearing stories about how AFCI's trip and they figure out why. I haven't had the pleasure (yet) of trouble shooting them. Heck, I just install an electronic ballast for the first time in my own house.
