I was working a few years ago as a Warehouseman for a major high street store, in Northampton. Warehousemen for the store, have to deal with goods deliveries, general maintenance, and locking/unlocking of the store too.
The unlocking of the store itself occurs very early in the morning, and just one of the warehousemen goes around the store turning on the lights, and unlocking the fire-exits.
One winter's morning, I had to do the unlocking of the exits - part of this includes a staircase at the back of the building that is enclosed in it's own giant stairwell, and connects four floors. The lights for the stairwell are key-operated, rather than a standard switch and the only other illumination comes from a frosted-glass skylight window in the roof at the top. So, it's very dark, it's cold too because it's winter-time, and I am fumbling about trying to find the right keys to turn the lights on; and I hear a slight shuffling noise coming from the top of the stairs....
I look straight up the stairwell, and I see the distinct shadowy outline of a dark arm and hand move away from the handrail at the very top of the stairs. I'm a bit alarmed, but assume it could be an intruder, I quickly find the key for the lights, and turn all of them on, then I go up the stairs, calling out repeatedly "Who's there? Who's there?" I make my way up all the flights of stairs until I have reached the top level. At the top, there is a doorway to the roof outside, and if this had been left open - then the intruder could have escaped that way - but it was locked. All the hairs stood up on the back of my neck when I realised that I hadn't found anyone, and no one had passed by me. I then remembered that I had gone from the second floor to the fourth, and there was a doorway to the third floor stockroom - so perhaps the intruder had gone 'down' the stairs and hidden in the stockroom?
I went down towards the stockroom; finding a light switch in there isn't easy because they are on long cords for fluorescence that hang down and are difficult to find in complete darkness...only some of the light from the stairwell doorway could help me out, and to make things worse - the stockroom was full of mannequin dummies lying about all over the place! I found some of the light switches, and turned on, as many as I could - but still couldn't find the mystery intruder. This didn't leave me feeling scared, but just a bit confused about what I thought I'd seen.
I didn't tell any of my colleagues at first in case they thought I was mad; but later that day I told my experience to a close friend at work. He'd been working there for many years, and when I told him what happened, he didn't seem too shocked, "Oh yeah that's the ghost of old Harry!" he said quite casually. "Who?" I asked, my friend explained,"Yeah, Harry was a warehouseman who worked here a long time ago, and he died of a heart-attack up there, on the fourth floor - that must be who you saw!"
Well, I still wasn't completely sure it was the ghost of the former-warehouseman, but I also never liked unlocking on my own in that stairwell after that and I always made sure I turned on the lights quickly first. The very early hour of the morning at which I was doing the task makes me believe that I wasn't fully awake yet, and perception could have been blurred enough to trick me in to thinking I saw something there that wasn't.
Sent in by Matt Robin