[Mr. Rogers]

Normal open, red wire (end)

Middle leg, white wire (middle)

Normal Closed, black wire (end)

This will read false when not trigged in the code, true when pressed. If you don't know which end leg is which, just look on the side of the limit switch. The diagram will show the middle leg connected to a side leg (normal closed)
Plug into a digital I/O, pay attention to the orientation on the digital side car.