The number calls and leaves no message. If I call the number back, it says it is out of service.

an automated call did not identify the group calling, but wanted to conduct a survey regarding the most important political issues in Petaluma, CA. I consider this SPAM since they didn't identify themselves. i imagine this is some kind of political front group or political consulting agency. sketchy!

Robocall.  Political front group pretending to be a survey.