Originally Posted by readermom123
Are there any types of small appliances that should definitely be avoided because they contain mercury/strong capacitors/anything like that?

As someone has already mentioned, avoid televisions (non-flat screen) and CRT monitors, as you can get a hefty shock.

There is lead in solder, so definitely have your kid wash his hands after handling circuit boards. I'm not sure how much, if any, would rub off onto your hands, but better to be safe.