Identify this movie where a woman is backing away from a rat-like creature?

I think it's a common one - I've certainly seen it several times before. This movie has a short clip of a black and white film where a woman is seen (who may have locked herself in a laundry room - details are hazy) backing away from a furry mass with a tail, a bit like a rat/brain combination. It wiggles, she screams, and the clip ends.

Any ideas? The clip isn't scary at all, by the way, and I think the "outer" movie's a comedy.