The real Mrs. Shusham was the librarian at the old Coolsville Public Library.
She disappeared after it was closed down, and it's unknown if she is really deceased.
A Pup Named Scooby-Doo
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)