On the official site for "Identity", a sound clip plays of someone saying " When I was going up the stairs, I met a man who wasn't there. He wasn't there again today. I wish, I wish he'd go away."

Sounds like something from a poem or a song. Anyone know where it comes from or if it was written for the movie.

http://www.sonypictures.com/movies/identity/

It's poem by Hughes Mearns:

http://www.lyfe.freeserve.co.uk/manwhowasntthere.htm

Thanks!