Demons don't exist, and their mythical properties are ascribed to real addictions. Addictions may not be incurable, they may not be uncontrollable, they may not require exorcism by an expert, they may not have been induced by sin or fed by it, Jesus may not be the answer, etc.

edit: really? Happy to accept the downvotes on this one.

Again, it's a metaphor. You know, like "I'm so hungry I could eat a unicorn" But unicorns don't exist you say!

Agreed. Historically this "evil spirit" metaphor has been a symbol used to deny accountabilty for everything from battery to rape and murder. It also includes religious baggage.

A homunculus didn't do it; I am it and I did that.