What's this wire/Connector go to?

[GoldHawg]

I need to connect all the wiring back off from my frame off and I don't remember seeing this wire until I pulled out the inner fender yesterday (to get new e-brake cable in). What's it to? TIA!

 

[pacecarta]

prop valve brake switch, its supposed to have a black (squeeze to release) retainer sleeve on it

 

[GoldHawg]

Thanks much!