Old Haunts (Haunted Guesthouse #3) by E.J. Copperman.
Alison Kerby's ghosts are depressed. If you haven't read the earlier books in this charming series, Alison Kerby owns a large old house on the Jersey Shore that she has turned into a guesthouse (NOT a bed and breakfast!). When she bought the house, she didn't realize that it already had residents: the ghosts of Maxie Malone and Paul Harrison who had been killed on the property and seemed unable to leave.
As if handling these two relatively reasonable requests isn't tough enough on top of running her guesthouse, a very unexpected visitor turns up on Alison's doorstep: her own ex-husband, affectionately known as The Swine. Claiming that he wants to get back together, he sets about ingratiating himself with their daughter Melissa. But Alison knows him much too well to believe him, and is certain that he's up to something.
Alison and her precocious daughter Melissa improve upon acquaintance, although it's something of a relief that Melissa is still young enough to believe her father's promises. It's difficult to feel that way about The Swine or the ghostly enfant terrible that is Maxie, even though we're quite aware that we're seeing them through Alison's eyes.
Although this series does have a paranormal premise, it can in no way be described as horror. The ghosts are benign, and their interactions with live humans is often hilarious.
*FTC Full Disclosure: Many thanks to the publisher, who sent me a copy of the book for review purposes.