Forgot about the ghost in Nidarosdomen, the cathedral here in town, of course. There's said to be a monk wandering around and singing psalms there at night.
And not far from my house is the local Museum of Justice. Cell 11 is supposed to be haunted by a judge, who after his death understood he had sentenced a young man to rot in this cell for a long time, the prisoner took his own life. Unknown whether it's haunted because the judge is being punished, or because he has decided to pay for what he did to the innocent man. If it's true though, of course.
Then there's the Colonel, who's more of a friendly ghost. He spends his time haunting a tavern, screwing around with the lights and moving the furniture around.
There's another museum (for ships and stuff I think), where people have observed a ghost presumably from a slave murdered on the second floor in the 1800s.
And then there's one haunting one of the malls and other nearby buildings in the middle of town.
Still though, few of them reach the level of fame ghosts do in other countries. Only knew about the monk before I looked into things actually. It's hard to explain the norwegian attitude towards ghosts and other supernatural stuff. I think we're very used to "respecting" things as the Draug for their value as cultural heritage. And thus most ghosts that are observed are usually connected to buildings and events with some sort of historical value.
Another thing is that the ghosts seldom seem to be dreadful or gory, missing limbs or leaving trails of blood and that sort of thing. When observed they seem to hold the opinion that their appearance and disappearance is enough to convey the message they want to send.
For the record I've never seen a ghost, and consider myself merely a curious skeptic.