Chances are that he lives close, like within a couple hundred feet. If he
causes
interference to a cheap portable radio, you can listen while walking up
and down
the street, then look for an antenna. If that doesn't work, get in contact
with
a local ham club. Someone there will probably be willing to pinpoint the
jerk.


Indeed. Walk the block, find out where the interference fades in each
direction, and your new friend will probably be smack in the middle of those
points.

Local ham club will have better means, but it sounds like this guy won't be
hard to peg.