The Alfred Hitchcock Hour (1962)

Season 1: Episode 7

David Kelsey, a research chemist, is in love with Annabel. He assumes another identity so that they can share their moments together in complete privacy. He even builds a beautiful dream home for the two of them. David is hopelessly infatuated with her. Unfortunately, Annabel wants no part of him. She's married and both she and her husband wonder when David will get the hint. He does not and eventually murders the couple. He installs her corpse in the bedroom of their dreamhouse so that she can be by his side for the rest of his life.