87 hatch strut light?
 

I noticed a box mounted on the hatch strut, it looks to me like a light but not positive. Has anyone else seen this? Is it factory?

post a pic, let us see what u see. possibly just something a previous owner put there.

My '86 has the hatch light mounted there

86-88 had the light mounted to the hatch shock. 89-91 had them low in the hatch area.

Its likely the hatch light. They were standard on the 86-88 as mentioned above. Would be interested to see a picture of what you have to confirm.