Mystery electrical thing that lives on top of the transfer case. It wasn't used on our Jeep, I assume it is for some option that we didn't have? View attachment 82941
That's the connector for the torque converter's lockup circuit for the 32RH automatic transmission. It's there whether or not the TJ has a 32RH automatic transmission.
Most vehicles have a standard wiring harness they use and cap off the options that aren't used for your vehicle. I installed fog lights in a vehicle once that had the wiring harness already for it. Just had to buy the switch, lights, and mounting hardware. Looked like it came from the factory with the option.