Caller ID says "Auburn   MA".  They leave no message.

I call back after hours (using *67 to block my number).  Their outgoing message is about 30 seconds of silence.  Then it hangs up on me.

So they have a spoofed caller ID with a message that doesn't identify themselves.  This smells like a SCAM to me.

Based on similarity to other numbers and caller ID's, I am guessing this is likely some solar panel SCAM.