This is the simplest possible way to power
an LED off 115VAC. I epoxied a high-brightness yellow LED into the switch plate to
my garage light. The light switch is inside my house, but the garage light cannot be
seen when the door is closed. This has caused me to leave the garage light on
overnight many times until I created this solution. I have outdoor light that could
use this solution as well (when I get around to it).
This circuit was soldered together, wrapped
with electrical tape and tucked inside the electrical box containing the garage light
switch. A small hole was drilled in the switch plate for the LED to stick out of.