They called twice and left no message. I called the number back after seeing it could be PG&E - and it was. They were calling because I am on the CARE program and it was an automated sequence of questions to requalify me for participation. They do this every couple of years I think - don't remember frequency.
I wish they would have left a message so I didn't have to go hunting down who it was, but anyone on the CARE program I suggest calling back because it's an easy few minutes to go through requalifying application vs doing it all by paper.