I take it that you are dealing with some type of 3way switch, which just basically is an on-on-on type switch, the ground wire shouldn't bother you unless you don't like playing an electric guitar. Mini-toggles are just small toggle switches, you can find them in all the standard configurations, on-on,on-off-on, on-on-on, you might just want to go with a push/pull pot, just a pot with a switch attached, if I get the drift of what you want to do, it would be easy to do with your 3way switch, a push/pull pot and about 2 inches of wire........ Have you checked out these websites:

http://www.guitarnuts.com
and
http://www.guitarelectronics.com

If you can solder, and like to experiment, for less than $10 you'll be able to do about any mod out there, have fun...........