Do you believe in ghosts?

My dad didn't believe in ghosts but had a strange tale to tell. He and my mum stayed with an old lady in Rotherham. Her dog wouldn't enter the back bedroom and stood outside it barking. One night my dad heard what he thought was a party going on downstairs. He went down and entered the back room. The door slammed behind him and all sounds of the party ceased. Years later they went back to visit the old lady and found the house was for sale. The Estate Agents said the lady had died and they couldn't sell the house - it had a reputation for being haunted.