Det ska vara Black Sabbath (1963), särskilt den tredje berättelsen, som heter "The Drop of Water".
Från Wikipedia:
In London, England, Nurse Helen Chester (Jacqueline Pierreux) is called to a large house to prepare the corpse of an elderly medium for her burial. As she dresses the body, she notices a sapphire ring on its finger. Chester steals it, [...] Chester finds the woman's corpse lying in her bed. It rises and floats toward her.