I remember reading a story about a demon who is trying to make a man insane or send his soul to hell (or both).
The demon goes to the man's home and tries to terrorize the man, creating a haunted house environment, with creaks, groans, bad smells, poltergeist-type activities. But the man is unperturbed and continues on with his life as if nothing unusual was happening. This goes on for a long time, possibly many years.
The end result is the demon is the one who goes insane, and in a final twist it is revealed that the man knew about the demon the whole time. The insane demon then becomes a slave to the man.
That is pretty much all I remember from the story - I read this when I was a kid, which was around the late 80s / early 90s - I am not 100% sure when the story was set, but I think it was in the 20th Century at some point. I think this was a fairly short story, maybe a novella? I remember the twist at the end being pretty good which is why the story has stuck in my mind all these years. Can anyone help me find the title/author?