I had this happen last year - 2 men rang my apartment doorbell, claiming to be PSE&G. No worker's gear, they showed up at 6pm, and their only "official" part of the costume was holding an iPad. I opened my window to see what they wanted - They said they wanted to talk about what I owed on my bill and I told them I'd contact PSE&G in the morning. They gave up pretty quickly but still, it was concerning.