When I was in Denmark in 1993 I visited my childhood home which I had left when I was 10 years old.
The people living there then had just bought the house the year before. When they saw us taking a picture of the house they invited us in to see it.
The home was built around 1900 and had not changed much; the beech wood planking was still there, it can last forever.
While talking with the new owners they asked us if we had ever seen a ghost there. They explained that one evening the Lady of the House was sitting in the living room with their dogs, three large Belgian-German Shepherds, when she heard them growling. Looking up she saw the grey shadow of a lady standing in the doorway at one end of the room.
It then vanished and later her husband, a military professional man, also saw the ghostly lady.Neither one mentioned it to the other until one evening they were both sitting there and the dogs growled again. Then they both saw it the grey shadow of a woman.
The Belgian-German Shepherds dogs are used by the militia for tracking down illegal migrants coming across the Baltic Sea to the beaches of Denmark. This appears to be a strong clue that they are sensing something in the room, so maybe there really are ghosts.