Package-bomb

Yesterday (Wednesday, October 25) we had a package to mail: a return-exchange of pull-on rubber galoshes.
The drill had been to mail it at the West Bloomfield post-office — a revenue issue — but timing was becoming impossible. This is because the one-person post-offices like West Bloomfield close for lunch 12:30-1:30.
So we went to the massive Canandaigua post-office instead, which has no lunch-hour.
“Anything liquid, perishable, fragile or potentially hazardous?”
We could imagine the following exchange:
“Well, it contains a package-bomb.”
“Well, let’s see if I have a package-stamp for that.”
“Yes I do; ‘Caution: package-bomb enclosed. Handle with care.’”
“And here’s another: ‘Personal. To be opened only by addressee.’”
“Would you like a confirmation-of-receipt?”
“Sure. Preferably signed in blood.”