In Three Men and a Baby, there IS a boy who is standing in a doorway that just doesn't make sense to the story. This is either because A) it's a mistake and the ghost story was a coverup B) it's just a publicity stunt and they stuck the kid in on purpose, or C) it's a ghost. The bottom line is that if you look for the kid, he's eerily clear. No vague shadows here. The appearance is brief, but there's no doubt that it is a boy. There was all kinds of publicity around this and stories emerged of a young boy who passed away in the flat in which they filmed. Still, I think it was just a mistake, but the other actors don't seem to notice him standing only a couple feet away. Watch it again and decide for yourself.