74: Family terrorised by anonymous letter writer | Who was THE WATCHER?

In 2014 the Broaddus family bought their dream home in Westfield, New Jersey. All the preparations were made to begin some serious renovation work before they moved in when an anonymous letter arrived from someone who referred to themselves as 'The Watcher'. Thinly veiled threats were made to the family's children and this person professed to be part of a long line of people watching the house, generation after generation. Who were they and what was their motivation?