mfarraday, I love your story idea and the suggestion that M G Kizzia made. That would give a lot of motivation for the ghost not to help in the mc's quest (therefore conflict, which is always good).
As for finishing something, I hear a lot of writers start with the ending, then go back to fill in the details of the story. Maybe that could help you finish something. I know how hard it is to put the pieces together at the end after trudging through most of your novel.