From Emily Fuller Drew’s card file:
In early days, all public meetings both religion and secular were held in the old meeting house and all notices of meetings were posted on the front of the meeting house for parish and town were one. After the formation of separate religious bodies and the building of the Town House, certain notices continued to be posted nearby the meeting house, and for this purpose, a small bulletin board was set up on the post where the wall of the burying ground and the fence around the Green met. This was the Town Post, the post and bulletin board where town notices were posted. Notices were certainly posted there until 1911 and I am told there were notices posted there later but not regularly.
The Town Post still stands just between the Training Green and the First Parish Church.