The real Mrs. Shusham was the librarian at the old Coolsville Public Library.
History
Early life
She disappeared after it was closed down, and it's unknown if she is really deceased.
A Pup Named Scooby-Doo
Season three
Bernice Binder disguised herself as her ghost in order to get her hands on a rare book Shaggy Rogers checked out and lost long ago: Pizza Parrot and the Butterbean Bunnies. (The Ghost of Mrs. Shusham)