The ghost and the haunted mansion - Alice Kimberly

When the local mailman inherits a haunted house and demands an exorcism, Pen must act fast to save her favorite ghost in this Haunted Bookshop mystery from New York Times bestselling author Cleo Coyle, writing as Alice Kimberly.

Bookshop owner Penelope Thornton-McClure didn't believe in ghosts-until she met the spirit of hard-boiled 1940s detective Jack Shepard. And when Pen's friend and mailman, Seymour Tarnish, gets into deep trouble, Pen not only believes in her ghost-she also thinks he can help...

An elderly lady of leisure has been found dead on posh Larchmont Avenue, her will recently, and suspiciously, revised to name Seymour as heir to her mansion. Just as eyes turn to him as the murderer-and Seymour gets busy settling into his ritzy digs-the mansion's ghosts begin plaguing him. So he hires a team of parapsychologists to exorcise all the spirits from the town of Quindicott-and that includes Jack Shepard. Now Pen must act fast-because losing Jack scares Pen more than rattling chains and cold spots...