I live in Philly PA area so, to me, this is a sorta 'local' call if actually coming from Levittown PA. Phoned my cell phone around 2pm. Showed as 'unknown'. It rang 5x's. Left no message.
Called at 1:58PM and rang for less than one ring. Called back immediately and I declined the call. It's a local call for me as well, but I don't answer calls I don't recognize. Another number to be blocked.
It's a landline in Carversville, Pa. Probably on/near Carversville Rd. or Saw Mill Rd. Could get the exact address from Spokeo website for 95 cents, but not that motivated. One ring? Five rings? Sounds like some kids. Or could be some "Big Brother" way of pinging your cell phone to get a GPS location on it. Best thing to do is exactly what you did... don't answer it, and don't phone back. If they repeat it, -block the number.