I want to push a button in one place and have a buzzer go off (also LED light) about 50 feet away, wirelessly. Kinda like a remote doorbell.
I used a pair of RD-11s from Swift Enterprises. They provide about the simplest solution to this need I can imagine. It would work equally well for any 1-bit sensor, like a pressure plate or magnetic door/window sensor, and any 1-bit 5V output like an LED, buzzer, or 110V relay to turn on AC equipment at a distance.
I have a video of how I did it, here: http://tinyurl.com/3qtrusc
(And yes, I am the creator of this device. But this is a real project I did, and I'm posting here as I think it is of real use to the folks in this section of the forum).