Connecting Sain Smart Mechanical End Stops to Ramps 1.4?
The multiple connections are redundant. Your picture indicates the wires labelled as "SIGNAL, GND, GND, VCC". This is correct if the board is a "standard" mechanical endstop v1.2. The two middle pins are both ground, but you only need to use one of them.

You can simply connect signal to signal and ground to ground. That is sufficient for the endstop to work. You only need to connect VVC to VVC if you want the LED that's on the board to function.