The utility that served Cape Cod and Martha's Vineyard Island at the time was the Cape and Vineyard Electric Company with headquarters in Hyannis. A lot of their local distribution was via 4kv primary typically supported by medium-size porcelain cabletop insulators. My family visited the Cape and its beaches many times during the 1960s and I always was fascinated by these cool-looking insulators. Most of them were medium-to-darker shades of mottled tans and browns while others were orange-ish. I believe some of these were of Pinco manufacture. Many still remain to this day in Cape Cod communities on older poles where 4kv primary is present.

In addition, telephone openwire lines were fairly common for subscriber lines until the early 1960s. An example is seen here. New England Telephone had converted most of this to paired plastic-sheathed cable by that time. Of interest, NET&T Co. also offered cable television service to many Cape Cod cities and towns, commencing in the early 1950s. Antenna reception from Boston and other cities was rather poor, so this service was fairly popular.