The Atlantic Paranormal Society (TAPS) are a group of ghost hunters, they have their own show called Ghost Hunters. In six seasons they haven't found a ghost and yet the show is still on the air doing well and Firefly gets cancelled after 11 episodes. It beats the hell out of me, I guess our world is insane.
If the best evidence that you have for the existence of ghosts is footage of people running around creepy places at night scaring themselves then you really haven't got beyond square one. It's not that I don't want ghosts to exist, if there was compelling evidence for ghosts I would change my name to Egon and build a proton pack. I've already got a ghost plan (but not a zombie plan).