I found this mystery plug loosely tucked under the dash. It appears to be attached to the same bundle of wires that leads to the passenger compartment fuse box, but I looked at the fuse box and it didn't seem like there was anywhere for it to go. It could be from something aftermarket added by a previous owner, they did some pretty poor wiring for some aftermarket lights that I removed, but I'm a bit stumped and am honestly lost in the sauce looking at wiring diagrams.

 

Can you pls take a better picture of the red thing on it ? Is that a clip?

 

yeah its a clip