"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 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...