I recently took my dash apart on my 1999 Yukon( not the first time I've had to do this) and I noticed a plug that goes to nothing still wrapped in factory foam. It's like it's missing the option that it controls but I have no idea what it's for.

Location of mystery harness--
Behind main dash bezel that goes around gauge cluster, radio, and heater controls.
Access panel on left side of radio that holds rear wiper switch, rear cargo hatch release and a blank spot.
It appears by the location of the harness and the length that it goes to the blank spot.(removable panel)

Question is what does it control, what am I missing? I have not seen any yukon's, tahoe's or suburban's with a factory switch there. Help, if it's something I can add, I'd like to. Thanks