Here is Part I of III of the London Ghost Story:
I live on the top floor of a large detached Victorian villa. The floor consists of kitchen, sitting room, bedroom and bathroom. There is another room, in between the kitchen and bedroom, that is used for storage. Along the shared wall in the storage room are bookshelves, filled to the brim with books.
My landlord lives on the ground and first floor. He goes out several evenings a week to his club.
So. I had lived there for about six years when all hell broke loose the Curious Incident of the Book in the Night started.
It was a Saturday evening. My landlord had gone out at 8pm to his club so I was alone in the house. I was reading "The Demonologist" about the work of Ed and Lorraine Warren (there was a film about them a couple of years ago with Vera Farmiga). Anyway, at precisely midnight I turned off my bedside light (I was reading in bed) to go to sleep.
Immediately, a pounding noise started on the shared wall. I mean - really angry pounding - as though someone had a sledgehammer and was trying to break through the wall. The sound was about waist height - maybe a bit higher - and travelled the length of the shared wall.
I pulled the bedclothes over my head (yeah, brave I am not) and did the only thing I could think to do, which was to recite The Lord's Prayer. As a dyed-in-the-wool agnostic, it is the only prayer and the only thing I could think to do. As soon as I started to recite the prayer, the pounding stopped.
The next Saturday night was a carbon copy repeat of the previous night. At midnight (not by design but by sheer coincidence) I closed "The Demonologist", turned off the light and prepared to go to sleep.
The pounding started again. This time, it travelled along the wall, turned a corner and began pounding at a wall that was at right angles to the original wall. Again, I recited The Lord's Prayer and it stopped.
When I told people this, some people said "oh, it's an old house. They all make noises." Well, gee. I'd lived in that house for six years and knew all its idiosyncrasies - which floorboards creak, what the plumbing sounds like - and it was not like that at all.
Other people said "it was a water hammer. You know what a water hammer sounds like, right?". Yep, I do. And it wasn't a water hammer. What's more, there are no pipes in that wall - I asked my landlord. Plus, it's a Victorian house and the walls are thick: I've tried pounding on the wall and the most I can do is to make a dull thump.