I know some 110V extension cords have a little orange light that shows you if it is plugged in. How do these work? I am trying to build an indicator light like that but typical LEDs draw about 20mA, and off 110V that's still about 1 watt of power (assuming I'm using only half of the AC). So it seems like a big resistor + big diode + LED in series is not a good option. Is there any clever and inexpensive/simple way of achieving this? I need to make about 10-15 of these that's why I want a simple/inexpensive way of doing it. Thanks guys!