If he were going to physically harm you or your family in any way, he wouldn't be harassing you on the phone. He's legit just trying to scare you.
The best approach here is to "grey rock" him, which in this case just means not answering. You said you don't use the home phone so just disconnect whatever device. You said your wife has blocked him so that's sorted. Close your fb account or don't log in or whatever.
Call the police and make an actual report to get an actual report number. Here any kind of threat made over a "wire service" is a crime. They may not investigate but that's not the point, in the infinitessimal chance the guy escalates, you want some history.
Refresh home security without going nuts. Maybe a ~~ring~~ door camera, make sure window locks are installed.
Then just go about your life, but maybe avoid throw down arguments on fb.
Edit: don't buy a ring camera.