Ghost Wanted -- Carolyn Hart

Bailey Ruth is a vivacious red-headed ghost who serves in Heaven's Department of Good Intentions, overseen by a ghost named Wiggins, who occasionally send Bailey Ruth to Oklahoma to right wrongs.  There are strict rules for such jobs, all of which Bailey Ruth ignores at one time or another, though probably never so quickly as she does in Ghost Wanted.  

This time, there's another ghost, Lorraine Marlow, who'd chosen to remain on Earth rather than go to Heaven.  She passes her time sparking romances between library patrons by leaving them roses.  Unfortunately, someone else has started leaving roses and engaging in a bit of vandalism.  And this leads to murder.  Bailey Ruth teams up with Lorraine to help out the young woman falsely accused of the crime, while at the same time Bailey Ruth is trying to bring Lorraine and Wiggins together after the many long earthly years that have separated them.  

This is a great concoction with humor and romance as well as murder and a dangerous killer on the loose.  If you're looking for some fine seasonal entertainment with amusing ghosts rather than blood and gore, it's right here.  Check it out.