@Wilso,
I don't think it's that easy to jump on someone for not knowing something. I've wired houses with my uncle and dad since I was little, but I know most of friends have no idea how to change a lighting fixture, and would probably get a nasty jolt just trying.
In this day and age how can we expect people to know everything? I'm not a gearhead, I don't know the first thing about the mechanics of a car, so if I ask a question does that make me an idiot?
I watch DIY shows and I'm constantly amazed at how many people have never picked up a tool. But... they are probably experts in things I know nothing about. So the guy asked a question, better he asks than attempting something he knows nothing about and then, based on experts telling him the correct procedure, he can make an informed decision. What's so wrong with that?
Maybe, you should have told him to switch the breaker off and call an electrician instead of making fun of him. Maybe he just bought the place and a crooked inspector told him the place was A-OK only to find out the wiring was circa 1930's or he had a renovator do a shitty job. Who knows, but asking a question does not an idiot make.