When I first installed wi-fi in my house in 2001, one of my friends declared (jokingly) that he would be wearing tin-foil underpants when visiting. While he was joking, he was the kind of person who easily believes things they are told, and lets go of beliefs slowly. He did say he would never install it in his own house.

Yes, there is a widespread belief amongst the general public that wi-fi and mobile phones are dangerous.