Genre-specific premise: the haunting of a personal problem
A strong paranormal premise usually hides two stories: the external supernatural problem and the internal human problem. Your plot question should force characters to make choices under supernatural pressure. Examples of craft-level premise forms: 1) “If I can interpret this haunting, I can save my brother” (goal with a supernatural gatekeeping system); 2) “If I tell the truth about what I saw, the demon will stop using my voice” (truth as the mechanism); 3) “If I keep my bloodline secret, the coven won’t take my daughter” (family and rules as the engine). State the internal problem early through actions, not backstory. Then let the supernatural escalate it rather than replacing it.