This 1978 made for Tv ' horror movie' is directed by Wes Craven and stars Linda Blair, here sporting a perm much scarier then anything in the exorcist.
She plays Rachel who's family take in her cousin Julia after her parents die in a car crash, and who then proceeds to charm the rest of the family and generally try to usurp Rachel at every turn.
A bout of hives,a couple of strange wax dolls with hair on ,a stolen boyfriend and a dead horse later Rachel begins to suspect there might be something a bit fishy about Julie.Who might as well have had the word WITCH tattooed on her forehead for how little she's tried to hide it anyway.
Of course this leads to an epic battle of magic and untold horrors as Rachel tries to save her family from the evil sorceress.But as this is a 70s TV budget that just involves a wind machine and some funny contacts, followed by an occult and mystical ( Checks notes) err car chase.
Personally I felt Witch curses were probably only slightly less creepy then Rachel's brother who spends the entire movie trying to get Julie to go out with him and yet not one person slaps him and points out that she's his COUSIN. But hey I'm old fashions like that.