ok, I heard this story from a female co-worker. She is no liar.

She used to work on a local elderlies carecenter and was this day walking a blind man through a tunnel connecting two separate parts of the complex, this tunnel is about 40m long and underground. When about halfway she told that guiding this blind man it felt like somebody ran past them and pushed her aside. She said she felt the shivers and thought it was her imagination that fooled on her, until this blind fellow said; Damn he was in a hurry.. I dont believe i ghosts until I see one, but this was in my opinion really scary story.