According to Veronica Carson, Director Freddie Frances made Peter Cushing do multiple takes during the scene where he talks about his love for his wife. This caused Cushing great distress, and reduced him, and some of the crew, to tears.
The photograph of Doctor Lawrence's wife is a photograph of Peter Cushing's own wife. She died suddenly in 1971 and Cushing mourned for the twenty years he survived her, often commenting that his only real joy in life was contemplating being reunited with her after death.
In the U.S., this film has been released as "Night of the Ghoul" and "The Thing in the Attic". Contrary to belief in some quarters, the film is not in the public domain, the rights holder is still Tyburn Film Productions.