For the switches it doesn’t matter. We’re just closing the circuit. That will work though. Positive to signal, negative to ground.
Don’t beat yourself up. Anyone who hasn’t trashed some electronics has never worked on electronics. Lesson learned.
Ok Thank you. I have plugged a end stop into the signal and ground and it has worked. I am not sure if this is what it is supposed to do though when ever the computer thinks it is a 0,0 I can’t move it into the negatives even though it has not hit the end stop.
There are two way to wire the switch, NO (Normally Open), NC (Normally Closed). For the MPCNC they get wired normally open, you have it backwards so it thinks the endstop is trigger and won’t move past it (negative direction). SO you should plug into COM and the middle lead.
Ah so all I need to do is flip the plug?
No. The wires themselves, 
You really should use them machine without the endstops, I promise using them is harder than plugging them in.
Why would using the machine with end stops be harder if you don’t mind me asking.
Ok that makes a lot of sense. Thank you for your advice. About the end stop wiring just so I know how to do it in the future a wire would always need to be on COM and whether you want NO or NC is determines which one you put the other wire on?
Yes, it stands for common.