On the control plate - the red wire that is soldered to the back of the pots is goes to the earth on the switch. Black wire off the back of the pot prior to the output jack should be the bridge earth. Red wire on the top pot going to the outer lug is signal from the switch. Its a bit hard to see in the photo but I'm pretty sure if you wire it as per the switch in this diagram it should work fine:

https://www.pitbullguitars.com/wp-co...s/pdf/JM-1.pdf

Don't worry about the Humbucker here - the wiring is still the same for the single coil - as all the wiring from the pickups to the switch is done it isn't included in the diagram.

I'm sure Weirdbits will be along to confirm or point out something I've got wrong