I found three wires in a box: 1 blue 10 AWG, 1 blue 10 AWG and one white 12 AWG. There is a 125 volt reading across the two blue wires and a 125 volt reading across one of the blue wires and the white wire. There is no voltage across the other blue wire and the white wire. When I shut off one 20 amp breaker the voltages disappear. Which wire is neutral and which is hot? I thought the wires might be connected to a double breaker but not so. Note: I am in Mexico and wire color conventions are not always adhered to.