I'd live there till i die.
You will need a young priest and an old priest.... Da Powa of Christ compells uUuuuu..... throws a bucket of water at u now.
Whatever you do, don't say Beatlejuice thrice.
nothing since I'd never believe in such things...
Make a film, post on youtube, become famous, get a lot of booty.
ask the ghost why it still remained, other stuff perhaps before threatening to destroy it unless it leaves.
Try to make friends with the ghost(s). Im sure a ghost is a powerful ally.