Snopes - the Urban Legend Archive - is a wealth of information on these things. Here's what they have to say:\n\n"The figure behind the curtains is a "standee" (a stand-up cardboard cutout used for advertising displays) of Ted Danson, dressed in a top hat, white shirt, and tails. The standee prop was created as part of a story line involving a dog food commercial in which Danson's character (an actor) appears, but references to the figure were cut from the finished version of the film."\n\n"(The standee shows up once more in the film: Ted Danson is standing next to it when the baby's mother comes to reclaim her child.) The figure was accidentally left in front of a window on the set by a propman and thereby "sneaked" into the background of one scene. Additionally, all indoor scenes were shot on a Toronto soundstage -- no real structures were used for interior filming."