This caller appears to be CUB, or the Citizen's Utility Board, an Illinois non-profit consumer advocacy organization. In the past my caller ID has displayed "CUB" as the calling party. This time only the number was identified. I was out when this call came in and my answering machine was off.

CUB is legitimate (I'm a member so that's how they have my name). Expect them to responsibly remove you from their database on request. They do not conceal their phone number (do a Google search) and they have a web site.

Unless someone is spoofing their number, in which case all bets are off. Probably safe to return a call to CUB to see if they actually phoned you. I no longer have complete confidence that phone calls are from whom they appear to be. Four personal emails in 2012, appearing to be from colleagues, proved scams. One installed several viruses. My new rule is to provide no personal information over the phone: no account numbers of any kind, pin numbers, email addresses etc. No family names. No answering "survey" questions.