Seems to be a typical issue.

The center brake light [housing] on the rear screen has come loose. I've considered using clear silicone calk or sealant of some sort. I'm not sure this is the way to go ... is this the proper fix? Does anyone have a success story fixing this seemingly simple repair?

 

Caldercay, yes i do, i used super glue like stuff, make sure it says it will bond too glass, let see mine fell of i think about 6 or 7 yrs ago, still on ther as of today, i do remember i had to keep pressure on it for awhile, and i think i put something under to hold in place while the bond cured over nite
Geno
1995 xj6 186k miles