I believe in ghosts, theres more than just us!
Seriously though, theres too many pictures and events in this world that point to strange things like ghosts. I've personally experienced something like that when I was in a castle for a wedding party, it involved the top floor and lots of books being thrown at the door. When we went outside there was nobody there.
Plus we were on a kind of ghost hunt, and the castle is apparently haunted by lady Lumley. So, it was a scary thing..and I personally believe in ghosts