Torches dimmed, radios going haywire and a voice on the stairs asked 'are you all right mum?'
Were these merely a sequence of easily-explained phenomena, or were the former occupants of Normansfield Hospital really trying to communicate with a team of 'sensitives' and ghost hunters?
The debate could run and run, but from my own experiences of the seven hour vigil there seems to be more resting inside the fabric of this magnificent old Victorian building and its museum than meets the eye.
Situated against the backdrop of a drizzly windswept Autumn evening, the headquarters of the respected Down's Syndrome Association seemed the perfect setting for spooky encounters.
Staff at the Grade II Listed Victorian building claim to have felt themselves being pushed from behind, seen ghostly figures walking through the buildings and heard a piano in the main entertainment hall play by itself.
There have also been reports of poltergeist activity and loud footsteps echoing around the building.
A Shaman who recently visited the building claimed to have felt negative energy in several areas and believed a phantom was holding back many others from passing over.
It was this which led The London Paranormal Society led by Ian Shillito of television's Most Haunted fame to conduct its own experiment.
We were equipped with cameras, thermometers, microphones, two-way radios and other psychic paraphernalia used to detect any paranormal activity.
Following a briefing, and guided meditation for protection, we were split up into teams with each group covering designated areas of the building, including the attic, entertainment hall, backstage, museum, stairs and the basement.
Before the vigil started we were being given a tour and several people, including me, heard a voice say 'are you alright mum?' as we filed up the stairs.
A normal occurrence, you may think, although the person who we thought had said it didn't. This was a promising start.
A couple of brave souls agreed to keep solo vigils for a while in parts of the building.
There didn't appear to be much happening until they left the room when the cameras picked up Orbs (balls of light who some believe are spirit energies) flying around the room.
In the pitch-black attic a woman said she felt someone touch her head or back of her hair, although no ghostly hands were detected on the night vision cameras.
During a back stage vigil, as the London Paranormal sensitives called out for the resident spooks to make contact, fresh torch batteries inexplicably dimmed.
Apparently it is quite common for spirits to drain energy like this before they manifest.
There were also interesting experiments in table tipping and electromagnetic voice phenomenon (EVP), where we unsuccessfully tried to capture ghostly voices on a tape machine.
A lot of strange noises could easily be accounted for when group members moved their chairs or shuffled in their seats to collective panicked gasps, only to declare 'sorry that was my leg/arm'.
Others though weren't so obvious. What were those flashes of light near the stairs? Who's was that voice asking 'are you alright mum?'? And was it really my imagination or tired eyes that saw a flash of blond hair beside me in the gloom of the back stage? I guess I will never know.
Maybe the inhabitants of this apparently haunted institution really have taken their secrets to the grave. It was fun, if not scary at times, finding out and I would definitely recommend you try a similar event.
For information on other vigils visit www.londonparanormal.co.uk