Instructions
Start "The Sims 2" and select the neighborhood that contains the household with the problem ghost.
Click the icon for the house on the neighborhood map to enter the household.
Wait until daytime. Ghosts appear after 8 pm, and you can't remove their graves while they are out haunting.
Click the "Buy Mode" button to enter the area where you purchase items for your Sim's home.
Click the tombstone object on your Sim's lot and press the "Delete" key. This will remove the grave from the game and remove the ghost as well.