In a nod to Johnny Depps character in A Nightmare on Elm Street, Harvey appears wearing a cropped t shirt bearing the number 10 and a pair of old headphones.
When Sabrina, Ms. Wardwell, and Hilda are leaving the Spellman house, the shot pulls out to reveal a multi-colored skylight in the sitting room. The pattern of the skylight is the same pattern that features prominently in the movie Suspiria (1977), which also deals with witchcraft.
When Zelda says, "What have I done to deserve these women in my life?" and Ambrose replies, "lucky, I suppose," this could be a nod to Hocus Pocus when Winifred Sanderson asks why she's cursed with such idiot sisters and Sarah gives the same reply.
When Sabrina, Hilda and Ms. Wardwell approach the Putnam house the light from the windows are falling down on the street like the iconic poster scene from The Exorcist.
A poster in Harvey's bedroom features the cover art for "Mad House" #96, a horror comic published in 1974 by Archie Comics, under its Red Circle label. (The cover features a woman standing in front of a demonic Satan, for the story "Demon Kiss".) Cover art from an earlier iteration of the same comic series, "Archie's Mad House" #13 (1961), is seen behind Harvey's bed. (It features Archie Andrews and classic movie monsters.) Sabrina the Teenage Witch, also an Archie Comics character, first appeared in the same comic series: "Archie's Mad House" #22, published in 1962.