I also received these calls at all hours.....no message, or when you pick up just static.  I have called back immediately and it says that the number is not working at this time.  Looked up some info abut Martin Nyberg, it refers back to a remodeling business....however, I do not believe this is true.

Nyberg Martin.  No messsage left.  Calls late

Hang up call .

called 3/8 and 3/11 and hung up just before answering machine picked up. caller id "Nyberg Martin"