"It's A Madhouse"

[Timotheus]

Here's a random question (I'm full of them): I recently heard the song "Madhouse" by Anthrax for the first time (fun song). There's a voice over at the beginning where you hear a medicine cart goin down the hall, and you hear the nurse say "It's time for your medication, Mr. Brown" and then there's this funny but scary laugh that would put :crazy: to shame, followed by the song actually beginning.
Has anyone else who has heard this song, and know where this beginning part came from? It sounds like it might be from a movie or something...