Simkits.com sells GA type circuit breakers... relatively expensive though. But luckily they provide a pdf document for download that shows how they did it.
And Stephen built one himself as you can see :-)
Its actually pretty simple. The core ingredients are a pushbutton (seen on the far right) and a small relay(center) without housing. The knob that extends out through the panel (on the left) is just a piece of a stick for a glue gun.
For the original, look for "Circuit Breaker Brochure" here: http://www.simkits.com/brochures.php
The frame is made from surplus PCB material, a couple of screws and nuts, alu pipes and a spring.
Here is a top view, the circuit breaker in closed(normal) position. The thicker piece of alu pipe is the key here: it "locks" with the movable relay contact.
And here the same in open position, ie. the circuit breaker "popped" out. To let the circuit breaker "pop" you apply a voltage through the relais coil.
