Harmless Ghosts is a booklet of three short stories by Jessica Amanda Salmonson. (The title is ironic, for the ghosts are not really harmless....) All are concerned with investigator Penelope Pettiweather, and take the form of letters written to friends about her supernatural experiences. The first and longest story, "The Hounds of the Hearth," is the best, but all three are enjoyable ghostly tales. Subsequent to reading this booklet, I have learned that the complete Penelope Pettiweather stories are collected in The Complete Weird Epistles of Penelope Pettiweather, Ghost Hunter (2016). This volume contains fourteen tales. I'll add this to my wants list.