Don't feel too bad, we've all done things like that at one time or another.

Here's one for ya:

One of the locals sold a nice FT-301 (All solid state HF rig of the 1970's-1980's). at the swap meet one time. The fella that bought it called the seller in a couple of days and complained that the thing went up in smoke the first time he turned it on ! He was very mad at the seller until he found out what happend........... Turns out that he put an A.C. plug on the end of the red and black wires and plugged it in and turned it on!

Faint !

73, John, K6YK