The town centre office in Liverpool Terrace dates back to the 1820s and is a large four-storey building with a basement.
Property company House Buy Fast moved there in 2009 and it seems that they may not be the only occupants.
The strange occurrences began in 2010 when director Jonathan Rolande was catching up on some paperwork on Sunday evening.
He explained: “It was a dark and misty evening and the building was empty. I was working in the first-floor office, which would formerly have been the lounge.
“As it was after 4pm, the local shops had closed and the whole area was quiet… ghostly quiet as it turned out.
“From nowhere, I heard the very clear sound of a little girl practising musical scales.
“I jumped up and looked out of the window but there was nobody in the street. The building was deserted but I could hear it clearly, as if she was just a few feet away.
“I felt quite spooked so went to make myself a coffee, convinced that I was imagining it.
“The kitchen is well away from the street and it was here that I heard strange talking noises, but not any language I recognised – almost backwards talking really.
“At that point I decided to leave.
“As I closed the glass inner door next to the street I saw a shadow move across the hallway and my first thought was that it could be an intruder. The alarm was set and I expected it to be triggered but it didn’t make a sound.
“Whatever I saw wasn’t picked up by the movement detectors. It was all very strange.”
And Jonathan isn’t the only person to hear things.
Colleagues Mario Antunes and Lewis Foster were working late one evening in 2013 when they heard people walking up the stairs.
Again they thought it must be intruders and followed the sound up the stairs but found nobody there.
Then, as they were walking back down, they saw a ‘misty shape’ moving in the stairwell below. Mario said: “It’s the only time I can honestly say that I really did see a ghost.”
Other staff members have heard doors and radiators banging, as well as children’s laughter and door handles being turned with nobody on the other side.
The company recently commissioned local historian and author Chris Hare to look into the property’s history.
The most interesting previous occupant was a certain Mrs Fanny Tranter and her two daughters, who ran a girls school there in 1881.
Could this be the reason that children’s voices are still heard to this day?
The office was recently featured on Fuji TV as part of their investigation into haunted property in the UK.
The presenters could hardly believe that staff would be willing to work in a haunted building, but the team at House Buy Fast take it in their stride.
“It’s all pretty weird,” says Mario, “but we’re used to it now. If something happens we hardly mention it anymore.”
Visit housebuyfast.co.uk to read more about the spooky goings-on in Liverpool Terrace.