No they don't. I've said it before, but you have the data, which are noises, sights, or lights. Your interpretation of that data as a ghost is not warranted. It's certainly not scientific. I'm not saying it isn't ghosts, but every other remotely plausible explanation must be discounted first. And by remotely, I mean remote control robots, which I can prove do exist. Why does no one who doesn't believe in ghosts ever see a ghost?