A833 Transmission leaking at reverse light switch
I would have to clean it off and watch it to be sure, but it appears to be coming out the very end where the two contactors exit the plastic center of the switch.
Yes this is very common and every new one I ever bought from the dealer also leaked there.
Here is the cure;
you will need a spraycan of Brakleen, a package of two-part epoxy( JB-Weld is ok ) compressed air, and a bench vise.
1) clean the outside
2) clamp the switch in in a vise, contacts down, depress the ball, then spray the Brakleen in behind the ball, then blow it out with the compressed air.
3) repeat steps 1 and 2, until you are sure the bases of the contacts are free of oil.
4) the leak points are around the bases of the contacts, and also where that black whatever it is, is crimped into the metal housing. So clean it all real good.
5) mix up your epoxy, and cover all that black stuff, Work it into the openings around the contacts, and into the perimeter crimp, as best as you can; then put a good thick layer over the entire base to a depth of about 1/8 th inch, including over/around/and down the outer crimp. Clean the contacts as may be required. 6) let it harden; then reinstall it, and forget it.
Just so you know, I have repaired numerous of these factory switches in the same way, including ones in the which, that black part was broken and/or with physical parts missing. It works every time; and I have never had a comeback.