With them, they carry a board, a glass and scraps of paper, ready to try and communicate with "the other side" by using that tried and tested method, a ouija board.
With the beam of one torch, they quickly assembly the papers, with letters of the alphabet and "yes" and "no" slips, into a circle, put their fingers on the glass and begin to ask questions.
The glass moves - accusations of pushing are denied - words are spelt - then the teenagers' nerve breaks, and they run back up to the safety of a lighted home.
Sound like the plot of a bad Hollywood movie? Sorry, but this is an (almost) true story - I should know, because I was there.
It wasn't quite the dead of night, more like around 11pm, and sadly in the height of summer rather than at Halloween but the rest is fairly accurate.
I have to put in my own disclaimer at this point and say I don't believe for a moment there was anything supernatural going on, just a good bit of trickery and willing group delusion.
But if people are looking for places to try their luck at communing with spirits at Halloween, Wales seems to offer an amazing array of sites to choose from.
Staying in the north, a medieval ghost with a very guilty conscience can find no rest at Ruthin Castle in Denbighshire.
The Grey Lady, who has been sighted roaming the castle, is said to be the wife of the castle's second in command during the time of Edward I.
According to legend, she murdered her husband's lover with an axe and was executed.
Her body could not be buried in hallowed ground and she was buried outside the battlements, where her grave can still be seen today.
These are just a drop in the ocean of Welsh haunting stories.
As Halloween descends once again, I would bet anybody a witches hat there will be groups doing exactly what we were doing all those years ago - using ghostly legends trying their best to scare themselves silly.
But will they make contact with anything other than an overactive imagination.....?
Tell us about your paranormal experiences around Wales:
When we renovated our house about 5 years ago, quite an interesting piece of paper fell from the chimney.
On the outside it had a "star" like shape drawn on it. When we opened the paper, it appeared to be a magic spell, cast on the house to protect it from evil spirits. So far so good....touch wood!
I used to live in Station Road, Cwmbran in south Wales in an old Victorian building.
This place was a rambling affair with many rooms. One night I had been left in what would be called a parlour and I glanced at the window.
Staring in through the window was an old lady with white hair and very large spectacles. This window which she was looking through was at least 5 foot off the ground, so unless they had brought a stool or such I don't know how it would of been possible. The room felt cold and I legged it from there.
Safe to say I am always cautious when looking through windows at night.
As a porter in a hospital in Cardiff (10 years ago), I was told to take a wheelchair up to a gentleman who had fallen on the ward. As I got into the lift to go up to the ward I saw this bloke in the corner of the lift and he was wincing as if he was in pain.
I tried not to look at him, but he did look in pain so I said: "Are you alright sir?"
He just shook his head and muttered: "Too late son."
My floor came about and I got out of the lift, looked back and this man had looked better because he was smiling as if he had had his pain suddenly alleviated.
I got on the ward concerned and was told by the staff nurse, that I was "too late".
As I thought I was going to get a rollicking for not being quick enough with the wheelchair, I apologised, to be told by the staff nurse "its not your fault the gentleman died".
I looked on the floor and it was the same man in the lift that had looked in pain.
I kept this story to myself for some years until I met some woman who had had the same experience and she said that the guy in the lift might have actually have been the spirit that had left his body. The smile he gave might actually have been him passing to the other side as if the pain had gone.
Kevin Powell, Wales
My grandfather was the caretaker of Cyfarthfa castle school in Merthyr Tydfil around the time of WWII. My father was a young boy at the time and actually lived in the caretakers accommodation in the castle. One Sunday, when he was about 4 years old, he was playing outside and my Grandmother called him in for his Sunday lunch.
He wanted to continue playing so she left him outside. Some time later he came running in, looking terrified, and saying that he had seen the "Bogeyman" in one of the windows of the castle looking out over the courtyard. My Grandmother thought nothing of this until later on in the week when my father and her were in the museum in the castle.
On the wall is a portrait of Crawshay, the builder of the castle, to which my father pointed and said "Bogeyman". Another interesting story concerns a Chinese vase that was kept in the cellars of the castle.
The vase was used for keeping flower bulbs. One day one of the workers in the School was leaning over the vase a! and had a strange feeling that he was falling into the vase.
He called my grandfather and described what had happened, so my Grandfather said, "Try it again". On the second attempt he felt the same falling feeling. After some investigation it was found that the vase was used in the Boxer Rebellion in China to catch the severed heads of executed rebels.
Ian Edwards, Virginia, USA
My home is in Little Haven, Pembrokeshire, a large house built in 1890. When I purchased the property in 1993, an 85 year old woman, who lived in the village, exclaimed "oh Mr Ritchie, you know you have a friendly spirit living in your home"! Yeah right, I thought...
I moved in just before the Christmas and the first thing I noticed was that when going to bed and switching the lights off, some would come back on and with the wall switches being operated.
There was a door between the kitchen and the main entrance hall I wanted to put a new lock on (not the Yale type) but whilst the key would work perfectly, with the lock not fitted to the door, as soon as the lock was screwed to the door, even loosely, the key would not turn and broke when forced. So had to make do with a bolt.
In one particular bedroom, the hot tap would be turned on in the dead of the night and then be turned off again after a few minutes.
This is just but a few of the many unexplainable events.
One Saturday, three of us were sat in the kitchen and breakfast was cooking in an oven grill, when I saw a well defined dark shadow, a Victorian maid, glide through the back door, passed in front of the cooker and into the lounge. All of us saw the same vision. In the afternoon I went up to see the local vicar, who exclaimed, "I wondered when you were going to come and see me".
First I had a blessing done in one room that was always cold, no matter how much heating was on. The blessing didn't help. Then the vicar held a communion a couple of weeks later. That helped, the room is now warm, but there is still a presence, the lighting and water tap events still occur, but not as often and no further sightings.