Therefore, its known narrative elements are not a part of the Doctor Who universe as we, on this Wiki, choose to define it. It may have been the basis for a similar story in another medium, however — and that story may indeed be valid.
Century House was an unproduced script written by Tom MacRae. The script was intended as the tenth episode of the fourth series of the BBC Wales Doctor Who. In it, the Doctor joins a live broadcast of paranormal reality show Most Haunted, investigating an old house purportedly haunted by the "Red Widow", while Donna watches at home.
The script was dropped because Russell T Davies felt that the story's comedic tone was too similar to that of the seventh episode of the series, The Unicorn and the Wasp; they were originally planned to air back-to-back. He was also unsatisfied with the premise he'd given MacRae. The companion-lite script was replaced by Davies' Midnight. (REF: DWMSE 20, The Writer's Tale)