Hit up concord in general - sleepy hollow cemetery has graves from the 1600, all the revolutionary war stuff has rumors of hauntings. Hart well tavern sometimes does ghost stories by candlelight in the old inn.

The wayside Inn in Sudbury also has a few resident ghost claims, plus George Washington stayed there and it was mentioned in a famous poem. You can go for a reasonably priced meal, explore the nearby gristmill, and walk around concord all in one day.