A few years ago a wrote up an adventure using the song Delta Dawn as inspiration. Dawn is a ghost. The PCs goal is to help her reunite with her love. She is buried in an unmarked grave somewhere. The back story is her love's family didn't like him slumming with a townie. They hired a couple of thugs to disappear her. She died in the attempt. When the son found out he killed his family. Now the whole family are undead in their hillside manor.
The PCs find her remains in the swamp under a bunch of ghost roses. They take them to the manor to be with her love.
Pretty neat, eh? It was my first real attempt at writing one. It's mostly just encounters with very little story. I thought I would flesh it out once I ran a group through it. I was reminded of it after listening to One Night in Bangkok. That one might be interesting fodder for an adventure.