This experience happened to me back in 2012 whilst I was running the pharmacy at Headley Court, the UKs main rehabilitation unit for injured servicemen.
The pharmacy was a very small room and I used to run it single handed, so there was only ever me in the room, except if I was dealing with a patient.
One afternoon I was sat at the computer when I heard a noise, like something had dropped on the floor. Not heavy but almost like the noise a pen would make if it fell. I looked around at my feet as I assumed I had dropped something from the desk but there was nothing there. When I got up about 5 minutes later to start dispensing the next prescription I noticed there was a yellowy coloured pebble on the bench which was very smooth and round and clean. There was nowhere that it could have come from. The window was closed and nobody had been in the room. I wasn't scared, I didn't feel uncomfortable. I was just puzzled!
I had no explanation for it at all. I asked the practice nurse, who was in her room at the time if she had heard or seen anything but she hadn't.
The medical centre was in a building that used to be the stables many years ago and the pharmacy was adjacent to the officers mess, which was a very old building. Nothing ever happened again but for a long time after I kept the pebble in my pocket every day I worked until I left the following year.
It just got me wondering if anyone has any stories regarding haunted UK army bases in Germany as that is where we are currently based.