Tormented

A 1960 "Horror" film, directed by Bert I. Gordon.

Jazz pianist Tom Stewart is engaged to rich girl Meg. Unfortunately for him, his possessive former flame Vi shows up intending to disrupt the nuptials. Fortunately for him, Vi meets him in a dilapidated old lighthouse; and when she falls through the rusted guardrail, he refuses to save her. Exit Vi. Problem solved.

Turns out Vi's spirit is still hanging around, "tormenting" Tom and still intent upon wrecking his wedding. Or, is it all in Tom's head?

Well, no, turns out it's Vi's head.

After about an hour of ghostly cat-and-mouse, a beatnik boater arrives and, deducing what has happened to Vi, begins to blackmail Tom, forcing him into action to protect his secret. This, however, is witnessed by Meg's little sister, Sandy. Tom is about to off Sandy as well, but Vi's ghost arrives and finally exacts her revenge.

For the Mystery Science Theater 3000 episode see here.

Tropes used in Tormented include:

Accidental Murder: In the opening of the film, Vi falls off the railing without any intent by Tom...though technically, it's not an accident as Tom chose not to save her.
Arc Words: "Tom Stewart killed me! Tom Stewart killed me!" A bit misleading, but "Tom Stewart stood there staring without lifting a finger while I pleaded for him to save my life!" doesn't quite have the same ring to it. You could probably call it murder by inaction, though.
Asshole Victim: Vi is a pretty much loathsome person that nobody really feels sorry for. The Milkman is much the same way, as he cares less about justice for Vi and more about getting blackmail money. It's hard to feel sorry for Tom as well, of course.
Betty and Veronica: Vi and Meg, though admittedly it doesn't last for long.
Bittersweet Ending: Tom is killed by falling from the lighthouse, which he kinda deserves...and after his and Vi's bodies are found, Vi's arm slumps over him possessively. The film closes on the newly-widowed Meg's horror and the mentally-scarred Sandy's tears.
Blackmail Is Such an Ugly Word: "The way I see it, you an' me... we should be partners."
Blind Seer: Kinda...The blind lady seems able to sense Vi on some level, but doesn't appear to realize she's a ghost until Vi tries to kill her as well.
Broken Pedestal: Sandy idolizes Tom. Then she goes into Heroic BSOD when she sees Tom commiting some evil acts.
Clingy Jealous Girl: Vi
Evil Laugh: Vi.
Have You Told Anyone Else?: Tom ends up saying a near equivalent to this towards Sandy.
He Knows Too Much: Scuzzy beatnik boat guy and, eventually, Sandy.
Hey, It's That Guy!: Richard Carlson ("Tom") was also the star of It Came from Outer Space.
Informed Ability: Tom is allegedly a great jazz pianist. Allegedly.
I See Dead People's Heads: And they won't shut up!
It Won't Turn Off: The record player.
Karmic Death: Vi's ghost forces Tom to fall from the lighthouse to his death, in much the same manner as Tom had allowed Vi to fall to her death.
- And they wash up together on shore, holding hands in death. Um, awww?
Kick the Dog: Subverted; Tom is about to kill Sandy, but instead dies his Karmic Death. She's also a highly unappealing character, so breaching Infant Immortality on her part might not have worked as a Moral Event Horizon anyway.
Lighthouse Point: Most of the film's events revolve around the old lighthouse.
Losing Your Head: Vi.
Murder Is the Best Solution: Tom keeps arriving at this conclusion when a number of simpler ones would have availed him before going this far.
Oh, No, Not Again: Vi's method of haunting Tom has a parallel with a story of a previous tenant the blind lady tells Tom about. A boy and dog drowned nearby, and from then on, his parents felt seawater in his bedroom and could hear his voice along with the dog's barking.
Our Ghosts Are Different: They're just heads, for one thing.
Parental Marriage Veto: Meg's dad does not approve of jazz pianists, and blames the ruined wedding ceremony on Tom despite the obviously supernatural goings-on.
Precocious Crush: Sandy to Tom.

Tom (to Sandy): All right; from now on, you're the other woman in my life!

Railing Kill: Vi, and almost the blind seeress.

Sex Drugs and Rock N Roll: Tom is convinced that his relationship with Vi will ruin his career.
Stringy-Haired Ghost Girl: Vi doesn't have the look, but she's got the methods.
Title Drop: The record in the record player, which is "Tormented".
Together in Death: Vi and Tom. At the Denouement, when their bodies are discovered and laid side by side on the beach, her arm drapes itself around him and sports Meg's previously lost wedding ring.
Totally Radical: The hepcat freaky beatnik and his hip lingo.
Unfinished Business: Vi is "tormenting" Tom in order to get revenge for her death.
The Voiceless: Ghost Vi until she found her voice, and at that point Tom was even more tormented. "Tom Stewart killed me!"
You Are Number Six: Well, her watch has her name on it, "VI", and it's a mystery why anyone would think that's a name and not a Roman numeral 6.
- It's most likely short for Vivian or a stage name. She was a singer after all.