... Just be frank with him,..he should understand,..that putting peoples lives and property at risk is no laughing matter.. Be firm, but not condescending.. Ask him to take on less technical jobs until he grasps the concepts related to the tasks at hand.."You gotta crawl before ya can walk"..If he's enthusiastic enough about the trade,he'll take the neccessary training courses to do so..If not...then he really shouldn't be messin' with it..There are many other ways to make an honest buck..
...Just my 3 cents worth here,...I'm done.. [Linked Image] [Linked Image]

.."if it ain't fixed,don't break it...call a Licensed Electrician"