Phone had a number that said +44 2074035019.

207-403-5019
calls daily up to 25 times a day (15 minutes apart)
Calling the number back results in a constant busy signal
or constant ringing with a disconnect after ~50 rings

+44 means that it's from Great Britain.  I've received 2 in calls in about 2 weeks.  I'm not sure what it is as I've not yet answered the phone.  When I tried calling back I received a "your international call cannot be completed as dialed"

If these calls are coming from Maine, why do they use an international exchange?  I received a call from this number on 2/14.  I also received a call from +442074700092 just a few minutes ago.  I'll pick up next time and tell them to lose my number.