I saw this movie being a child (1990 to 1994 I guess), on Spansih TV, It was dubbed, but i’m pretty sure it is an American film, dating from the ’70s or ’80s.
There was a man whose house was somewhat haunted, and he could hear a voice in his head. I remember a scene where he is talking with this voice/spirit in the toilet, and the “ghost” appears as a plastecine little man, stop-motion animated, running over the border of the toilet.
I remember too that later in the movie, the man flies from his house and the police finds bones under the porch, and then this man goes (for reasons I can’t remmeber) to a water dam, maybe in the desert.
I’m not sure, but I think that Mr. Sandman song was included in the movie.
That’s all I remember, but the brief moments of the film I remember had haunted me for years, and I what to find it to watch it again.