You see, no matter how much you payed for your guitar cables, there will still be some level of hum produced by your rig, especially with an extensive pedal-board, or with distortion effects like fuzz-boxes so long as the circuit that is your rig is closed. In this instructable, I will show you how to add a noise-free killswitch to any guitar with a 1/4 inch output jack.
Step 1: Parts
-- A guitar, obviously.
-- A pushbutton normally closed momentary switch. It is very, very, important that the switch be normally closed, check the package carefully before you buy your switch.
-- A soldering iron.
-- Heat-shrink tubing (or electrical tape in a pinch) to make everything all nice and pretty, and to prevent accidental short-circuits.
-- Screwdrivers that can open up your guitar.
-- Wire cutters and wire strippers.
-- A drill with an appropriately-sized bit. Check the packaging for your switch to see if a mounting-hole diameter is listed, since this will help a lot. If you can't find a listed size, err towards a smaller hole, since you can make holes bigger, but not smaller.
-- You may also need a bit of extra wire if there isn't enough slack, a foot of stranded 20 AWG copper wire should be more than enough.
Step 2: Prep-work
Now you're going to have to figure out where you want to put the switch. Unless you're willing to do a lot of extra work, you'll be limited in placement options by where the guitar's control-cavity is. Once you've determined where you want to place the switch, carefully mark the position and then drill a mounting-hole for the switch. If you're drilling through the body of your guitar, drill very carefully through the front of the guitar so that if there is any accidental splintering, it will be out of sight. To minimize the risk of splintering, you should press very gently while running the drill at a high speed.
Step 3: Installation
Make sure to insulate all your connections, and test them somehow before you close everything up, especially if you had to de-string your guitar in order to install the switch. The best way I have found to test your wiring is to plug your guitar into an amp, turn on the amp, and then stick some ferric object (like your screwdriver) onto your selected pickup, or if you did not have to remove your guitar's strings, pluck a string; if you don't get any sound make sure first that the volume is up on both the guitar and amp, and then that your selector-switch (if applicable) is set to the proper pickup. If you get sound, then you're golden, otherwise go back and check all your connections.