Walkthrough
Talk to father Aereck and tell him you want a quest, he'll tell you there is a ghost that he wants you to get rid of. He will also say that father Urhney can help you and is in Lumbridge swamp.
To get to the swamp, go around the back of Lumbridge castle and the swamp is south, on the other side of the fence. To get around the fence, go through the wood to the west.
Father Urhney is located in the western section of the swamp.
Once you talk to father Urhney he will give you a ghostspeak amulet.
Head back to the chapel, wear the amulet, go into the graveyard and talk to the ghost. If you cannot find the ghost go to the building at the bottom of the graveyard and open the coffin, once you have done that search the coffin and the ghost will appear.
Talk to the ghost and he will say a warlock has stolen his skull. To get the ghosts skull back you must go to the wizards tower. Once in the wizards tower go into the room on the right and climb down the ladder.
You will be in the dungeon, follow the path round until you come to a door on the LEFT side. Go into the room and go to the end room. There will be an altar there. Search it, and you receive a skull. As this happens, a level 13 skeleton appears, you can either run or fight.
Now head back to the graveyard, open the coffin and put the skull in
