Most of those pics are bulshit, and have been proven to be so. But there is one, the one with the figure of a girl in the flames of the burning building is one that can\'t, or at least hasn\'t up to now be explained.
There was a documentary on TV a while back, where they were trying to disprove the authenticity of several supposed ghost photos. They had photography experts in from all round the world, along with scientists from photography companies. None of them could find any way to prove it as a hoax.
For the record, I neither believe, or disbelieve in ghosts, I chose to adopt a "wait and see" approach, even though I did have have an "experience" once, when I was in a darkroom at college which I already mentioned on these forums.