As I rushed home, I was intrigued to see my grandparents prepare for the thunderstorm. Grandma would cover a large mirror on the living room wall with a dark cloth and throw a blanket over the TV. Meanwhile, Grandpa would climb a ladder to remove the light bulb over the patio door. Then they switched off all the lights in the house and waited the storm out.I never understood why they did all this. When I asked, they said that light attracts lightning. At least that was what people said, so better to be on the safe side.Where do these kinds of beliefs come from?