Edward Mordrake: Part 1 - S4-E3
Factual error: Season 4 takes place in 1952. Elsa sings Lana Del Rey's Gods and Monsters. The lyrics say "living like Jim Morrison." Jim Morrison was not famous until 1960. He was born in 1943, which would have made him only 9 at this time.
Edward Mordrake: Part 1 - S4-E3
Factual error: During the Bette and Dot surgery dream, we see the bone saw machine brought in and it says "Easymatic 300." In actuality, the machine is the power source for an X-Ray machine and wasn't produced until the early 1980s, while the season takes place in the early 1950s.
Chosen answer: Because on Halloween, the souls of The Dead are said to roam the Earth. That includes those souls that are trapped within the walls of the "Murder House".
THGhost