Here's a book published by Royal Prussian Academy in 1909 Inscriptiones parietariae Pompeianae, Herculanenses, Stabianae: https://archive.org/details/inscriptionespar42zang
You can browse inscriptions at http://ancientgraffiti.org/Graffiti/ Property type has e.g. brothel, inn and tavern for the more raunchy stuff.
