I used to work in a generation station that was part of a hospital complex.
This premises also had incineration plant and laundry facilities, so that all the heat energy that would normally be wasted could be used to some good purpose.
The result is that there were underground walkways to other parts of the hospital so that stuff could be moved around.
They had planned to build a bigger hospital, so there were a couple of tunnels that had been started and blanked off until the day these new buildings were contructed.
Meantime, were were short of storage space, so our manager suggested that we could use some of these blanked off tunnels to put stuff in, like spare new laundry items.
We had already put a few laundry trolleys down there but without lighting it wasn’t really that much use since you couldn’t tell what was on the trolleys.
No problem, we gave the job of installing all the cable conduit and light fittings to our apprentice, its exactly the sort of thing you do with an apprentice - give him a job where he can’t do too much damage, but he can learn a bit of task management - so it became his baby.
In the meantime, the rest of the maintenance crew dropped various hints about hospitals, and how many people die in them, and maybe this place is haunted - which it reputedly is - We were also careful to mention the history of the place since its a couple hundred years old, and how the site was originally old housing in medieval times.
So we sent our rather wary apprentice down the hole, it’s actually got a lift to go down to it but ‘mysteriously’ this wasn’t working so he had to use the access ladders.
Took him a few hours to get all the kit down there, his bending and setting vice, all his own tools, drills, extension leads, ladders and parts for installation - it’s a good old way to climb up and down umpteen times with all that gear.
Of course we did ensure he could see whilst down there and ensured he had a penlight, powered by a couple of throbbing AA batteries.
One of the older semi-skilled workers decided just a take it a smidgeon further - these are the guys who carry the kit around, upmarket gophers if you like and its pretty normal for them to have a go at ‘edjamacating’ apprentices before they get passed as fully skilled licensed tradesmen.
He bided his time until our hero left the hole for his tea break, then he crept down there and hid in an empty laundry sack - these are quite large things, you can readily stand up inside one and look like some amorphous blob, add in a few moans and groans and you have the very thing!
Twenty minutes later and the apprentice goes back down into the hole, his eyes aren’t quite used to the low light from the penlight torch having just come from a well lit canteen.
Meantime…as the apprentice passes a laundry trolley a large amorphous blob starts moving.
The trouble with laundry bags is that they have a self closing fastening on the drawcord, you can’t open them from the inside, so our ‘ghost’ starts struggling with it, not knowing that the apprentice is down there too.
The ghost is still trying to be as quiet as possible, he doesn’t know he’s being watched and he tries to slide the top of the bag around to where he can reach it more easily.
In doing this, he stumbles but can’t move his feet enough to keep his balance and falls flat on the concrete floor at the apprentices feet, and makes a very genuine groan and loud gasp.
That does it ! This finally finishes off what left of the apprentices’ nerve, an amorphous blob has just attacked him and he runs …
he shot out of the hole, up the ladder and it took the bewildered supervisor along with the works manager to grab him rugby style - they had only come along to inspect progress.
