The Top Secret Top Coat - S2-E29
Continuity mistake: When Hogan and company are getting ready to listen to the sock from "Aunt Alice" they plug the coffee pot up to their recorder. As they do so, the light that indicates power is lit up, but then Lebeau plugs in the power cord.
Answer: It's a comedy, not a documentary.
stiiggy
Perhaps it was counterfeit. There are numerous episodes where they deal in counterfeit monies.