several calls daily to my home phone
Are they stalking me?
This phone is an emergency only phone for 911 if needed.
I heard its a collection company, yet I don't owe anyone any money and am not past due.
Apparently this is a robo caller? Who knows.

I have received 66 calls from this number and no one speaks when I answer.  When I call the number, the mailbox is full.  I am on the do not call registry.  I do not know who they are.

If you're answering, that's why they're calling. Consider getting a call blocker, try blocking the number or let it ring without an answering machine taking it. Do not return calls to mystery numbers. DNC doesn't help with criminals.