I'm looking for a movie - possibly 80's. An old woman wears a bracelet on her wrist which summons an entity/force if she is threatened. Some villains attack and kill her. The entity/force takes revenge. The bracelet separates from her wrist. Some young people find her and pick up the bracelet. The bracelet locks itself on to the wrist of one of them. They don't know about the entity/force. Soon the entity/force starts killing people. Some of the action takes place in a museum. One man gets strangled on a ceiling fan. From then on, they try to remove the bracelet. I don't recall how the movie ends.
Thanks.