I'm trying to identify a novel or travelogue, possibly 18th century, possibly translated from French, which features as a significant tangent the story of a haunted painting. I believe the ghost story is presented with an extremely elaborate frame story regarding an orphan taken in by monks who would ultimately become a painter.
At any rate, the ghost story goes like this: the owner of a purportedly haunted painting wants to verify its status and tricks a guest into spending a night in its room while placing other guests in a room with a placebo painting which he tells them is haunted. The guest in the room with the genuine painting reports having had a tormented sleep. I believe this all takes place in Italy?
For some reason I'm strongly associating the book with James Tissot's painting "The London Visitors", which is of course 19th century, but covers are out of sync with subject all the time. The name sounds something like A Sentimental Journey, but it certainly isn't Sterne.
I should add that although the tangent is significant in context, it takes up only a few pages. I have absolutely no memory of the rest of the book.