The rumour that the show's makers had wanted to include a high-pitched tone that would agitate viewers' pets during the broadcast is mostly true. Writer Stephen Volk suggested it, but as soundtracks are 'capped' for transmission (meaning, limited in pitch, volume, etc.), even if permission had been secured to go ahead with the idea, technically-speaking, it would not have been possible.
While you may not see him 'Pipes' appears many times. To name a few: in the bedroom after the 'face-cutting' scene, behind the door to the cellar in the closing minutes, in the glass as 'Sarah Greene' picks up the posters, behind Parkinson at the end and even in the crowd at the Park as Craig Charles walks around - there are also many others.
Ghostwatch was never supposed to trick or deceive the viewers. It was billed as a drama and contained a "written by" title card at the start. The majority of people tuned in late to the programme after a film finished on ITV and therefore many thought what they were seeing was in fact going out live.
On the night of transmission, actress, Gillian Bevan returned home from the wrap party to find an answer machine message from friend and fellow actress, Judi Dench, who jokingly chastised her for inadvertently spoiling her enjoyment of Ghostwatch, having naturally recognised her in the role of Dr. Lin Pascoe, and thereby deducing that the show was in fact, staged and not live.
Writer Stephen Volk found his inspiration for Ghostwatch in a 'real-life' case from the late 1970s, referred to in the media as the 'Enfield poltergeist'. This case occurred in North London and involved psychokinetic activity (allegedly witnessed by police), as well as a spirit speaking through a young girl in a demonic-sounding voice. Much of the 'documentation' in Ghostwatch resembles that of the Enfield case, including the photograph on the cover of Dr Pascoe's book.
The 'Ghost in a Sheet' painting hanging over the studio fireplace is actually a print of an existing piece by Austrian-Irish artist, Gottfried Helnwein, which Stephen Volk first saw at an exhibition in Vienna.
The distinctive sound of Tunstall's disembodied, wailing cats can also be heard in 1987 comedy-drama, 'Withnail & I'; specifically, the first scene to feature 'Richard Griffith''s cat-loathing character, 'Uncle Monty'.
The strip of technical information displayed on-screen by Chris Miller's thermal vision scope is time-stamped whilst the camera is in operation, and had to be augmented in post-production to accurately read '1992-OCT-31'.
Phone-in caller 'Mary Christopher' is actually director, Lesley Manning, as the original actress hired for the role couldn't deliver the lines as intended. Likewise, the voice artist brought in to voice 'Pipes' the ghost was also substituted for Manning's own un-credited performance.
When the camera pans from Sarah making coffee for the crew, across to Mike Aiton, Suzanne Early can be seen hiding on the stairwell, listening in on the conversation. Later on, the same rack of six mugs which Sarah uses in this scene inexplicably becomes shattered after Pam Early declares, "We're all telling the truth!"
The grey BBC trucks as seen in the opening title sequence are 1988 British Leyland Freighters. Due to strict demarcation rules within the BBC, director, Lesley Manning had to choose whether to make 'Ghostwatch' either with a dedicated Studio crew or Outside Broadcast staff. This resulted in the show's 'hero' scanner truck effectively arriving on set as a prop, even though a manned O.B. Unit would have been perfectly outfitted for such an event.
Actively seeking out the latest on-screen graphics throughout the shoot, Lesley Manning utilised the now common 'Page Turn' effect before it was due to premiere on popular music show, 'Top of the Pops'.
The writer was unsuccessful in his attempt to be allowed to put a high pitched sound over the recording which while people wouldn't hear it would make household animals go wild - something which happens in the Pipes household and is frequently mentioned in the story.
Before Sarah Greene became the reporter at the 'haunted house', a number of other presenters were considered including: Joanna Lumley, Kirsty Young and Yvette Fielding. Fielding, who was a Blue Peter presenter at the time, was warned off hosting the special and in a strange twist of fate ten years later hosted the series 'Most Haunted' a show similar in style to Ghostwatch.
The on-screen map graphic used to show where phone-in guests are calling from was actually a printed artwork, filmed on set using a locked-off camera, vision mixed, and fed into the video-wall for the actors to respond to, 'live'.
At the beginning of the broadcast of the TV movie on BBC1, the BBC1 announcer said "Now on BBC1: Screen One presents an unusual, but sometimes disturbing film marking Hallowe'en. Over the centuries there have been countless reports of ghosts and ghouls. But the line between fact and fiction has always been unclear. Using the modern idiom of the outside broadcast, Michael Parkinson, Sarah Greene, Mike Smith and Craig Charles star... in Ghostwatch".
The trivia item below may give away important plot points.
In the early 2010's the BBC was planning a follow up mini series about the aftermath of this show and the evil released on the world as a result of the spirit possessing the broadcast equipment at the finale. However ideas were nixed as the original show was meet with harsh criticism for invoking panic in its viewers when first broadcast.