When I was about 12 I lived in South London, this was in the late 70's, we were a poor but happy family, and my knowledge of ghosts was almost zero.
A friend at that time came and stayed at our house for a week, we went to school together and shared my bedroom. We used to smoke in my bedroom. One evening I was lying at one end of my bed and my friend Gary was under the covers at the other end, we had a packet of cigarettes in the middle with an ashtray. I was allowed to smoke in my bedroom after being told off for smoking on many occasions, it was the sort of thing kids did in the 70's.
Well I went to get another cigarette and noticed the packet was missing, I thought Gary had hidden it, he thought I had, we searched the room and found it under a table at the other end of the room.
We still thought it was each other, so placed the cigarettes in the middle of the bed both lay down and after about 10 seconds looked and they were gone, we found them in the same place under the table again.
We did this 3 or 4 times and by now realized that it was not us doing this.
I suggested writing on a piece of paper is there anyone there and drawing a box under the question, I put it under the bed with a pen and after about 10 seconds checked again, the answer yes in scrawled writing could be read, we started asking lots and lots of questions like how old are you, your name, when did you die, what do you like, what do you not like, something's were answered but something's like age at death and year of death we could get a date and age but not an exact date and age within a few years as if the ghost did not want to give the exact date, we found it was a young man of about 18 years, of German origin who had died around 1918, he did not like the dark attic, liked being amongst people. He wrote that ghosts couldn't talk, though I have seen stuff on TV that states they can.
We asked how many ghosts were in the house and were told 4, also told they were good beings not bad.
This went on for a couple of evenings and then one evening when we got the paper from under the bed it had swear words for answers in a different hand, we thought it was our spirit friend messing about but eventually found out it was not, our friend could write sometimes but most of the time there was scribble and swear words, we found out that some bad spirits had entered the house and were taking over from the good spirits,
We asked if there was anything we could do to help, the good spirit said call for help in our minds, we tried this and eventually could get clear answers from the spirit that help had arrived and the bad spirits had been removed, during this time objects had been moved, sometimes in front of our eyes but usually we would see them after they had started moving or whilst in the air, this happened around the time of the swear words being written, when things had calmed down we tried some tests, putting small objects inside bottles covering them in newspaper and asking for the objects inside to be put in other rooms, this actually happened without the outer objects being touched.
Things got a bit strange when an object started moving under the bed cover, it was like a hand, we asked questions, shake once for no, twice for yes and found out eventually that it was a girl, I never looked under the cover at the hand as I was too scared to, though I was comfortable for it to be under the bed cover, Gary did and said it was white.
This girl spirit started doing strange stuff like taking cigarettes and putting them inside our underpants without us knowing, after a while it started scratching us with fine scratches about 6 to 8 inches long.
Gary got cross and kicked the hand under the cover and it no longer appeared.
We thought that was the end of it but the next night the room went crazy with objects flying everywhere, I had some heavy fossils and got worried that they would hit us so we started throwing loose objects into drawers this only got worse, when we left for school, objects would be thrown at us in the street even though my bedroom windows were closed.
I had a bible, school one like most kids Gary read from it and then dropped it to the floor, the activity died down and stopped, Gary went back home the next day and that was the end of it for a day or so, then it started again, this time I got really worried by myself and prayed for help to rid me of this, and it did work, it stopped all together.
The activities had something to do with Gary as lesser things happened on a regular basis at his house
My writing above may sound incredible maybe not but I have no reason to lie or make up stories the world is full of this type of thing for me not to bother adding to it.
Apart from this story I have seen a ghost once, as clear as anything you could see and seeing it really scared me, I froze and could hardly breath, all I could think was don't look at me, something about the eyes I guess, this was not at my house but around the corner in a derelict house, well, that is my true story that has taking all these years to eventually write