Hi
A Standard switch can be used, but you need to remove the switch plastic housing, and ream out the holes in the reciever box
I personally used a DPDT (Double Pole, Double Throw) switch from RS Components or Simular (Size: 23 x 8 x 19mm Mounting: 2 x M2 Tapped Screw Holes) and soldered it up myself.
As you look at the bottom of the switch (Top to Bottom) solder the following wires to the switch
CHG - CHG +
BAT- BAT +
RCV- RCV +
BE CAREFULL NOT TO TOUCH WIRES TOGETHER, AND INSULATE THE JOINTS AND DOUBLE CHECK - HAVE I STRESSED THIS ENOUGH
This means that when the switch is in the off position, then the battery can be charged, and when it is switched on the battery powers the reciever
I then reamed out the normal mounting holes in the reciever box so the switch could be screwed into place, and then sandwiched the switch in usnig a normal on/off switch plate (Or you can use washers) so that the screw heads did not go down the enlarged holes.
Total cost of conversion 1 AUD and some old Servo Cables / Connectors.
Hope this helps
Damo