The switch is for the voltages I would imagine. I don't follow you when you say the other end, as in the other end of the wire? It should just be copper, make sure your hands are clean when twisting the wire together, you should do it like in the tutorial with heat shrink tubing and solder, if you cant just be super careful, that's high voltage and high current available through that wire when its plugged in. Regardless of how you connect the blue and brown the most important thing is the ground wire, make sure both greens are connected together and connected to the metal case, securely and I would also run a thrid green ground wire from the screw on the metal cage to any other metal components in your set up.
This for your own safety, if there is no ground or it comes lose and if the brown or blue wire happens to touch any of the metal casing it would electrify the hole setup with 115Volts, and you could be shocked to death if you touch it, so just be careful and the green is most important!