I used to run a hangar with a ghost.
Working on your own there were often footsteps, sounds of doors opening and closing, etc.
Several times this happened when we were doing some severely "secret squirrel" work and the place was surrounded by cameras and motion detectors (and once when we had flooded the place with an unbreathable atmosphere and everybody was wearing oxygen masks).
No idea of the ancestry of our spook, the hangar had a long and interesting history, as did (does) the airfield, but there were no deaths in the hangar in working memory.
G