On the third picture the red wire is your power wire to the esc board! All the switch is doing is breaking the HOT ( red wire ) connection to your ESC or main board. If you go on the EL Mod site you can download the PDF on the Think Tank Booster K/M.

The very last picture in the lower right had corner give a good picture of how you need to wire the power! BUT look closely the tank that they used had black wires for the hot so it is confusing! You will only need two ground wires off the board & your battery connect into one going to the connection to the Booster! The two hots, One goes to the board and, One to the ON side of the switch! That way when you power your switch ON, both boards get power!

The Blitz