The Ghost on the Stairs - Crystal Cove Cozy Ghost Mysteries, #1

Sally O'Brian didn't always see ghosts. But when she and her husband were murdered, she discovered that she wasn't allowed to pass on through the Pearly Gates. She miraculously recovered but her husband is only with her as a ghost. She has to find out who had killed her husband.and may still be attempting to kill her. Sally also wants to help her young assistant Melody realize that her "fake" boyfriend Alan might have "real" feelings for her.
Ghosts aren't the only thing that Sally notices even when most of those around her are oblivious! But then Sally's neighbor "accidentally" falls down the stairs. The talkative ghost can't remember exactly what happened, but Sally is convinced that it was no accident.