Just freaking wait, no need to make 50 threads and get all mouthy when someone points it out.
You could wire it like people do portables, I know you're not making a portable. You would add the switch onto the power in.
Since I've never bothered modding an n64 or looking things up of this nature I will say, without much certainty because I haven't done it before, you could take off the switch, bridge 3&4, 5&6, etc, and wire up the switch to 1&2. Again, I'm not sure, as I haven't tested. Alternatively you could grab a multimeter, stop Segaing about people calling you out on spamming the forums with the same question, and *Can'tSayThisOnTV*ing test it yourself.