Rear diff sensor leaking

I'm posting this for a friend, which has a leaking sensor on the rear differential (see picture).

We'r having trouble finding the part number of this thing and associated seal and what it's supposed to be (e-locker sensor or ABS sensor ?).

Can it be changed just by pulling the little bolt out, or it may have some wires going inside the diff ? Any advice is welcome !!

It looks like the case to cover seal (rtv silicome) is what is leaking/weaping. You may want to try changing that first.

Pic may be confusing but it's not coming from the cover...It's sweating from that sensor on the side...

Anybody already had that issue ?