Here'e another phone prank from the Practical Joker.
The Noise War
There was a row of shops in a big long metal building and these two guys got into a noise war. One kept blaring his music, even though his neighbor asked him a number of times to keep it down. So the other guy finally takes action.
He gets one of those super loud phone buzzers that you hear out on car lots. So he puts this inside a 55 gallon drum and fastens the opening against the common wall. Now, whenever his phone rings, there's a horrendous noise coming out of the neighbor's wall, way more powerful than the music.
To enhance the effect,this guy will drive down the street, sit in his van with binoculars to observe and then call his phone number on a cell phone. Or, if he is going to be away for a while, he will go to a pay phone, dial his number and then just walk away and leave the phone off the hook.
MIB