OK this website has TONS of stories so you'll just have to read them for yourself. I'lll post links to a few that I've read though.

One about a dog http://www.castleofspirits.com/stories01/snowball.html
Long, but an interesting story
http://www.castleofspirits.com/stories01/bestfr.html
Another story
http://www.castleofspirits.com/stories01/longwalk.html

Ok I'm just picking random ones, I'm sure there are ones more creepy then these.