This is an electric company slamming scam, calling Pennsylvania telephone numbers. Caller leaves a message and wants you to call back so they can swap out your PECO energy bill with theirs. Caller left his name, a phone number, but oddly (NOT), no business name was left on the messages. It's a SCAM; don't answer it.

Received call. I did not answer. No message was left

Voice mail message left on machine.  As others have already said, it's a Pennsylvania utility bill scam.

Voicemail went something like this :
This is Mr Rivera.  I'm calling in regard to the supply portion of your electric discount here.
Be sure to call me back at 440-209-3706 with your electric statement to review this matter.

I received the exact same recorded message (twice!) from "Mr Rivera" today, as noted above by Roger That. I assumed it was a scam since he never used my name, never used his company name, and coughed in the recording (both times, same spot!). I kinda want to call just to see if I get a human being.