Outside of The Haunting, which also was released in 1963, this story (originally penned by Chekhov) called "A Drop of Water" from Mario Bava's trilogy of terror movie "Black Sabbath," scared me as much as anything I'd ever seen at the time. (Updated)
His use of sound is incredible.
And never, ever steal anything off a dead medium's body!
Film critic Ken Hanke wrote: "...the 'Drop of Water' sequence is about the creepiest thing ever filmed"
“A Drop of Water.” The story is simple, following a nurse who steals a ring off a rotting corpse only to regret it when the inevitable haunting begins. It’s style that makes the final entry the highlight, with Bava pulling out all the stops to make this a mind-boggling collection of gorgeous visual design and unsettling sound effects that hasn’t lost any of his creep-out power over the last fifty years. Bava is often credited as having inspired Argento’s string of gialli, but it’s also hard to deny after a viewing of “A Drop ofWater” that his work also helped pave the way for SUSPIRIA.