Moderators, if you think this is dangerous, feel free to delete this. I remember reading this technique in a fishing magazine a few years ago. What your doing is putting 120 volts into the ground and forcing the worms out of the ground. I did it yesterday and got about 50 nightcrawlerers in 1/2 and hour.
Grab a piece of wire coat hanger and cut it to a length of about 15". Stick in straight down into the ground so that an inch or two sticks out of the ground. NOw you need to connect 120volts to the piece of wire. Easiest way is to use and extention cord. On the extension there are two slots to plug into. The smaller slot is the HOT side. Push the small slot onto the wire in thte ground. NOW plug in the extension cord and in about a minnute, worms will start comming up after the ground. After you see enough worms, UNPLUG the extension cord, and gather them up.
If it's unclear or you want more info, let me know.