These folks called asking for person that makes decisions about the electric bill. Since this was a work number they called at, I told them they had the wrong number and who were they trying to reach. So they knew my name and also mentioned an address that i lived at 10 years ago (and not since then). Apparently it's one of those alternative energy suppliers working with PSE&G, JCPL and ACE (and no other NJ power companies) to offer me a lower electric supply rate. I told him that I don't live in an area serviced by any of those and he apologized. Considering that I'm on the Do Not Call list (just recently renewed also, for all my phone numbers), I'm guessing that PSE&G gave them the phone numbers of their customers directly.
Most times it is just a random dial. It will not matter if you are on the do not call list because they maintain they are offering a service and not selling you anything. Technically they will be working with your utility company not you so it is true.