You may have seen the LED Keeper and LightKeeper Pro gadgets in hardware stores by the Christmas trees ... one doesn't light up... "This is the bad bulb." There's a bulb tester built in.

When the only tool you have is a hammer, every problem looks like a nail. An LED ornament for the Christmas tree can be built in any manner of simple, easy implementations. You certainly don’t ...

A Christmas tree light tester is an essential Christmas light ... depending on your usage. Newer style LED (light-emitting diode) lights are the exception. LED Christmas lights can last 10 times ...