I have a two wire outside light connection that the tester shows has 122 volts. It lights the neon circuit tester also. When I connect a regular 15 or 40 volt light it will not light up. Obviously I tested to see that these work fine on a different circuit. I added a two pin plug to the circuit and this shows a light on the tester that says has an open ground. Nothing will power from this either. Can you show 120 volts but no amps? What do I do next to get the light to work?