Got couple last week. The Lowes cube (different manufacture)has an indicator light to let you know if elec is being released to the socket but only has one plug in the cube and about the same price. And you should be able to see if light is on anyway so Home Depot type is what we are going to use. The "light" part of your question had me doing some tinkering yesterday. The old fashion bulb(100 watt)we never had a problem in our shed (some canned goods)or RV. I'm not sure the newer bulbs will work so good. Much less temps are generated with newer type bulbs. So today going to collect old style bulbs from around house to keep just for the temps they put out and replace them with the newer low temp bulbs in order to have bulbs that actually do the job and prevent freeze ups. To test I put into freezer for about 1/2 hour and then tested with a light. So far so good. Home depot style packaging says "On at 35 and off at 45"