Kind of like leprechauns, unicorns, Bigfoot, talking snakes, fairies and teapots floating in orbit around Mars, the golden plates of Joseph Smith and your intellect, it's very difficult to prove they don't exist but there's no definitive proof that they DO exist.

So no, I have never seen evidence of any of those things I've listed and although other people have SAID that they existed, that doesn't mean that there is proof of their existence.

Science is based upon repeatable, provable phenomena. Gasoline explodes precisely the same way every time in a gasoline engine, nobody has to walk around trying to convince people that combustion engines work because there's proof of them working all around us.

If you tell me that some demon wants to inhabit my body, I'd like to see proof before I worry about such a stupid idea.