This is Sylvester McCoy's favorite serial of the twelve he starred in. However, he has admitted that he didn't understand it. He was quoted: "It was well done but God knows what it meant."
Many of the cast have gone on record saying they never fully understood what they were doing. Neither did the director.
The working script was heavily edited, with a number of explanatory scenes ultimately being omitted. The result is a plot that, unusually for Doctor Who (1963), generally needs to be viewed several times to be understood (and some reviewers have argued even that isn't enough to work it out). Even the cast and crew were confused by it. Patrick Mulkern wrote in the Radio Times that the story was "a shambles... as a piece of television drama it is incoherent and almost incomprehensible. The incoherence is ultimately Andrew Cartmel's responsibility. As script editor, it was his job to hone these scripts into three 25-minute episodes of prime-time drama."
Marc Platt drew from several Victorian literary sources in writing Ghost Light, particularly as inspiration for his characters. Mrs Grose was a lift from the character of the same name in another haunted house story, Henry James' 1898 novel The Turn Of The Screw. Gwendoline was originally called Maud, after the character Maud Ruthyn in the 1864 Joseph Sheridan Le Fanu novel Uncle Silas. The name had to be changed due to the BBC adaptation Uncle Silas (1989) set to air around the same time. Redvers Fenn-Cooper was based on H Rider Haggard's classic adventure character Allan Quatermain, who debuted in King Solomon's Mines (1885).