Was your ancestor an insurance agent or in the insurance business? Then you might be interested in A Catalogue of the Library of the Insurance Library Association of Boston (1899) available from Google Books. This is a catalog listing of books from the Insurance Library Association of Boston. You can learn more about the Insurance Library Association and research opportunities on their website.
While this is not a "genealogical" source it is one that includes some books with genealogical information, like names and dates. The chapter entitled "Insurance Almanacs, Directories, Year Books, Etc.", starting on page 96 does list directories of agents and others working in the insurance industry.
If your ancestor was part of the insurance business you may want to contact the Insurance Library Association of Boston and ask what types of materials they may have that might list the locality your ancestor lived in/worked in for that time period.
This is a great example of how you can research an ancestor's occupation by going to organizational associations and private libraries.