looking for a weird mod...

Hey guys, i fear its a bit of a long shot, but maybe one of you knows. About a year ago I saw a preview of a mod that was done (I think) from the Half life engine. Its very original, you play the part of a small piece of paper (thats right!), more like a white playing card with arms and legs. The environment is a home, in which you can literally hide between a frame on th wall and the wall itself...you can fold yourself and fit anywhere...its very weird and cool.

Anyone has the slightness idea what I'm referring to?

Well thanks for your help, always appreciated!