I've read stories about "good" ghosts - ones feeling a bit homesick and the like. Others make the point that the poor ghost in the particular tale is really seeking help but merely frightens the living who can help it find rest.
One of the best I've read was a wryly comic telling from the point of view of the ghosts haunting a house together (co-haunting?) - they found daylight and humans terrifying!
There's said to have been the ghost in a large house in my home county, of a previous resident who'd collected clocks. The ghost would do his nightly rounds, making sure his beloved clocks were all wound and ticking peacefully away! He disappeared after the clocks were sold on.
