Back in the late 70's, I was assigned to my first (and only) duty station at the Point Loma Submarine station in San Diego. I was an E-3 at the time.
The main facility was a tactical simulator installed in a freaking warehouse built in the 1890's. Point Loma had been Fort Rosecrans before being shifted to the Navy post-WWII. There were 2 normal outside doors, one in front facing east, and one on the north end, and one double-wide door in the back, facing west. The north door and the west double-door could only be opened from the inside. The front door was electrically controlled by a button inside a small office immediately beside the entry way. The facility was only open for training purposes Monday to Friday, 0700 to 2300. Enlisted personnel E-3 and below were put on a roster to stand a 24-hour watch over the weekend. We had to make hourly rounds to the several separated facilities until 23:30 the not again until 0530 the next morning. There was a small bedroom behind the office with a bed and tv.
Several of us noticed that starting at midnight, we would hear paced, regular footsteps in the attic, moving from north to south, then down the single stairway to the main deck, and then back northwards to the door to the bedroom. Then, a few minutes later, it would start again in the attic.
Now, there was only 1 stairway to the attic, so nobody could have hustled back to the stairway and upstairs without being heard. Only the front door was available for entry. So, we all figured it had to be a ghost.
The first time I heard it, I simply turned up the tv and stayed in bed