Film where a witch's hair and sweat are burned

Hi all, I wonder if you could help with identifying this movie for me. I've got just one short scene that I can remember. There's two women in a room, and a man appears holding some kind of bag and declares, "Here is the hair and sweat of a living witch!" One of the woman instructs him, "Burn it", and he takes out a lighter or something and proceeds to burn the bag. Then the other woman begins to shriek, presumably because she is a witch and that's her hair and sweat being burned. It would have been the 80s when I saw this scene on TV. I'm pretty sure it was a movie and not a TV show, and I'd guess it came from the 70s or 80s. Thanks!