Hey guys, I was wondering if this would work.

I took my Epi SG apart and I was looking at the wiring in it. The 3-way switch is what I guess is a standard 3-way switch. The bottom is like a rectangle, on one side are the red, white, and black wires. The red one comes from the rhythm (neck) pickup and is on the right, the black wire comes from the treble (bridge) pickup and is on the left, and the white wire is what I guess is both pickups together and is in the middle.

And on the opposite is a gray wire which I am assuming is assuming is a ground wire.

And the black and white wires are connected to the output.

So, is there any way that I can make a killswitch that goes on-off-on without having to solder or add any new wires, in other words, just by cutting a wire?

Also, I have pictures if I HAVE to upload them.

Slappa tha bass
The white wire goes to a lug on the potentiometer, so the short answer is no. But why don't you just turn the volume to 0 on your neck pickup and switch between positions 1 and 2?
Eh, I just had it all open and what-not and wanted to do something cool.

Is there anything worth doing that I could do right now for free and with no supplies?
Slappa tha bass
you could rewire your tone pots so you'd have 1 master tone and 1 new master volume (to go with the neck and bridge volume knobs you have already)

but it probably wouldn't be worthwhile, wouldn't really have much of a purpose.

If you're pickups were 4 wire you could re-wire a pot a do a coil tap, rather than using a switch. That's the only real useful thing I can think of that wouldn't require any additional parts