Horror Hotel

Also known as City of the Dead. From Wikipedia:
City of the Dead (US title: Horror Hotel) is a 1960 film directed by John Llewellyn Moxey and starring Christopher Lee and Valentine Dyall.

On the recommendation of her professor (Christopher Lee), a young female student (played by Venetia Stevenson) travels to a small Massachusetts town to do some research into witchcraft. She finds the town occupied by the reincarnation of an infamous witch (played by Patricia Jessel) burned at the stake in the 17th century.