On the off-chance: mad radio archives?

Related to an idea that smacked me in the head this morning:

Anyone know somewhere I might look to find archives of talk radio from the american midwest in the 30s-50s? Ideally, late night madbastards talking about their strange delusions? Think of the radio broadcasts that cut in at a couple of points during GYBE’s “Lift Your Skinny Fists…” if you’ve heard it or the sound of a small, broken person reading bits of Gene Ray’s Timecube, it’s that sort of thing I’m after.

Anyone?