Right side control switch question

[LMS]

Where would this black wire plug into? I would assume it plugs into ground but want to make sure as I can't find a black wire in the wiring diagram associated with this switch.
Thanks.

[1976RD400C]

On the switch I have that black wire is attached to the housing of the switch and the wiring diagram doesn't show it connects to the wire harness on the bike. I don't think you need to connect it to ground because the engine stop and light switches on that right side switch assemble don't need any ground connection.

[LMS]

I just took apart the switch and yep, same thing, attached to the body of the switch. I marked every wire when I took them all off, guessing the tape fell off. There is an open 4-point connector within the rat's nest, two are for the blinkers, one for the headlight, one open slot. These connect to ground on the headlight, I think it was connected to that one open spot.
Thanks for clarifying.

[1976RD400C]

After thinking a bit more, that may be to make sure the whole handlebar is grounded so the horn switch on the left side works because that needs a ground to work.