"Howdi, is this the FBI?"
"Yes. What do you want?"
"Well, you see I'm calling about my neighbour Billy Bob Jenkins. The thing is, he's hiding a stash of marijuana inside his firewood..."
"Sir, thank you very much for your call."
The following day, a crack squad of FBI agents descended on Billy Bob's house. Bursting into his shed, they find the stash of firewood. Using axes, they burst open every single piece of wood, but find no marijuana. They swore at Billy Bob and left...
The phone then rings inside Billy Bob's house:
"Hey there Billy Bob...Did the FBI come?"
"Did they chop your firewood?"
"Happy Birthday, Buddy"