This is a hinge for a dometic RV fridge. This is the part of the hinge that is screwed on the freezer door. It usually broke when you try to close the fridge door without closing the freezer door.

It is used with the parts below:

https://www.thingiverse.com/thing:1591564

https://www.thingiverse.com/thing:2009727

https://www.thingiverse.com/thing:6571535