2 years later, I'm working in the attic above this closet when I see
wiring
come out of the 'floor', go up a support stud to two wire nuts, and stop.
To this day, I have no idea what he was planning to use it for.

A switched light in the attic..is there a ceiling trapdoor in the closet for
attic access?
...or maybe there 'was' going to be one.

OR, run the circuit across the attic and out to a box w/ duplex outlet in
the soffit/eaves area

Gives you a dry outside place to plug in your "roof" Christmas lights and
switched "inside".
No cold wet trips outside in Winter to turn off/unplug the Xmas lights.

We have 2 such circuits Ho Ho Ho!