Ghost in the Post(2003)
(A book in the Little Terrors series)
A novel by Jan Burchett and Sara Vogler
George is delighted when his parents buy Little Frightley Manor, crumbling ancestral home of the ancient ghoulstone family. For a tumbledown caravan in the grounds houses the Little Terrors - a crazy bunch of Ghoulstone ghosts. And they're all kids.
Used availability for Jan Burchett's Ghost in the Post
February 1999 : UK Paperback