I would like to build a zapper from parts around the house or modify an existing electronic device that would have the same effect. (10hz-500KHz) 9-volt operated DC pulse (positive offset) output amps 5-10volts. frequency between 10-500,000 pulses per second. the frequency is the most important part. If you need the specifics:
Use Shoebox or Buy a Plastic Project Box
9 volt battery
9 volt battery snap connectoron-off toggle switchIf not available, choose any toggle switch with holes in the contact points or Radio Shack 275-612 1 K Ohm resistor, brown-black-red-gold3.9 K Ohm resistor, orange-white-red-gold39 K Ohm resistor, orange-white-orange-goldlow-current red LED.0047 uF capacitor.01 uF capacitor555 CMOS timer chip (TLC 555)8 pin wire-wrapping socket for the chipIf only 16 pin sockets are available, cut one in half OR leave half empty. Editor's Note: These parts have been discontinued at most Radio Shacks. 8 pin wire wrap sockets are available at many other electrical supply stores such as: www.PositiveOffset.comshort (12") alligator clip leadsIf not available, use 14" length from Radio Shack, 278-1156Micro clip jumper wiresIf not available, use mini-clip jumper wires 278-0162 bolts, about 1/8" diameter, 2" long, with 4 nuts and 4 washers2 copper pipes, 3/4" diameter, 4" longSharp knife, pin, long-nose pliers, tape, 4 twist ties or rubber bands.

Hi Maureen!

I know and built the zapper You are talking about.
It might not be too difficult to find this parts in scrap electronic devices, but difficult enough to dismount them, especially because one of them is a chip. But all in all the whole circuit is quite cheap.
I guess with 2 $ you get everything.
Ask if you need further help.

Greetings
Blue7Hand