Step 5. 

Connect the switch to a working adapted toy using a 1/8" to 1/8" connector (Radio Shack #42-2420)  

Press the switch.  If the toy comes on and stops when you release, then all is good.

If nothing happens then you probably over heated the switch when you were soldering on the connections - try another switch. Make sure to have a clean soldering iron and use just a little solder.

If the toy runs continuously, then you have a short circuit.  Make sure you that the solder has not connected too many things and that nothing is bent.