Inside the Bedroom Closet

There was a piece of drywall screwed into the bedroom closet wall that has been patched, so naturally I was curious what was behind it, primarily because I wanted to know if the guest bedroom and master bedroom closets were connected together at some point in the past.

Turns out they were not, since the shiplap was intact behind the drywall. That raises the mystery of why someone cut away just this piece of drywall. They must have had a reason...right???

Also curious is the peephole between the 2 closets. Perhaps it was once for a wire? One would hope!