Do you want a tone control on your guitar that doesn’t work like a standard tone control?
This modification is called the Greasebucket tone circuit and it was introduced by Fender in 2005, installed in some of their Highway One guitars and some of their Custom Shop Stratocaster models.

Fender says that this tone control acts differently because it rolls off the high frequencies but does not add bass. Actually, that is incorrect because this is a passive tone control (it requires no electricity) and cannot add bass.
Basically this circuit rolls off the high frequencies and the bass frequencies and just allows the middle frequencies to pass through to the amplifier.
This modification requires only 3 parts – two capacitors (.02 mfd and .1 mfd) and one 4,700 ohm resistor.

Before you begin, (as we’ve said many times), doing any unauthorized modification on your guitar could void your warranty or decrease its resale value.

This circuit should be quite easy to build. There are no holes to drill and the volume and tone controls stay right where they are.

There is the possibility that you might not want to use this tone control all of the time.
If that is the case, you might want to install a DPDT switch, which will switch the Greasebucket tone circuit “off” and (if the tone control previously used a .02 mfd capacitor), will make the tone control work exactly as it always did.

If you don’t want to change the appearance of your guitar, use a DPDT switch connected to a push-pull potentiometer. (Remember to use the same reistance value as the potentiometer you are replacing.)

If you choose to use a toggle switch, then it will change the guitar’s appearance when you drill a hole for that switch.

Good luck with the wiring.