When people ordinarily say things like "I believe ghosts exist", they're not referring to predictable patterns in horror stories. I can tell you some things about what the world would be like if ghosts existed, and the world isn't that way.
Right. When you extrapolate a model beyond its domain of validity, in this case from stories to the physically perceived world, the predictions of ghost models tend to fail pretty badly. So when people argue about what exists and what does not, all I see is "domain confusion".
I'm not at all sure what you mean when you say that all you see is "domain confusion". Do you mean that people in these arguments are talking past each other because they are each talking about different domains? Because I'm pretty sure that is not true in general. Or do you mean that people who say, for example, that ghosts exist are saying this because they are illegitimately extrapolating a theory that works in one domain into another? I don't think this is true in general either. Or do you mean something else?
Just to clarify: When, in ordinary circumstances, you encounter a debate between two people about whether ghosts exist, do you think one of them is right and the other is wrong?
What is something you used to believe, preferably something concrete with direct or implied predictions, that you now know was dead wrong. Was your belief rational given what you knew and could know back then, or was it irrational, and why?
Edit: I feel like some of these are getting a bit glib and political. Please try to explain what false assumptions or biases were underlying your beliefs - be introspective - this is LW after all.