Oddly enough, I simultaneously saw two different users in separate Facebook groups post about reading Shirley Jackson's We Have Always Lived in the Castle, both with this cover from the 60's paperback version, which I had never seen before. Instantly I recognized Mario Bava's Shock, a film I haven't seen in well over ten years and can't quit remember all that well, but I've always enjoyed the poster.
And, not surprising the art was copied over for the film poster, thanks to the, uh... extent of "borrowing" in Italian films, with about a fifteen year gap since the paperback was published. Interesting they took out the jagged wood to give the horned appearance, but I suppose a ghost with a box knife is plenty to get the point across.
I found this image on Tumblr, posted by someone who erroneously claimed it was the "inspiration" for the poster art. Some reverse-googling shows this is actually the art of Anthony Jimenez, who creates collage work out of old posters and VHS covers. Looking at some of his other work, it's obvious these are collages, seeing mash-ups of things like Rats: Night of Terror! and Return of the Living Dead, or the groovy skull surgeon from Death Warmed Up. Pretty rad stuff, regardless!