What do we think about ghosts? Is there a biblical basis for them, are they real?
The Bible teaches upon death, the person's spirit departs to glory or judgment. Read Jesus' account of the Rich Man and Lazarus in Luke 16:19-31. This passage clearly demonstrates that when we die, we go to paradise (with Jesus and His redeemed, including Abraham) or to a place of suffering (as the Rich Man experienced).
There is simply no biblical basis for a person dying but their spirit staying and hovering around the earth, frightening people.
What about people who have seen ghosts or a similar unexplained phenomenon? They are either intentionally lying, innocently incorrect - or have encountered demonic activity.