I remember seeing this when I was growing up, so it would have been made in the late 60s to mid-70s, and I remember it having the artificial brightness of something recorded to video at the time. (It’s possibly it was part of a TV anthology series.)
Anyway, a family (I think) moved into a house or castle that is supposed to be haunted. Various strange things happen, including a blood stain on the floor that comes back darker every time they clean it. In fact, it goes from red and then strangely turns green.
It turns out it is haunted, but the ghost (I want to say of an actor; I seem to remember him wearing different wigs for different hauntings) is fairly sympathetic, and possibly the central character. For a while I thought the ghost might have been played by Vincent Price, but I don’t see it on IMDB.
One of the family is a young woman who figures out the ghost isn’t that scary (and/or falls for him), since she figures out he was stealing her nail polish to keep making the bloodstain. He reveals (IIRC) that he’s under a curse, and that she has to walk with him through some ordeal to free him, during which she’d see terribly frightening things.
The last scene is her traumatized by happy, talking about the experience, and holding a box of treasure the ghost had revealed to her.
I don’t this would have been too much later than the mid-1970s.