Looking for a movie my mom watched in Mexico theaters 1975-1978, Horror Black and White

My mother recently told me she saw a movie when she was 10 in Monterrey Mexico about a woman who goes to a castle to care for an old man (she suspects it was the devil or some demon because he looked scary), in the castle there was a painting of a woman that was hundreds of years old that looked just like her as if she was a reincarnation or descendant. All you could really see from the old man was his hand extending outside the vail of his bed sometimes, he had long nails and a big ring on it, the woman had entered a contract with him/her/it of employment or something where she cant leave and she gets paid a lot, similar to the gary oldman's dracula movie.