Then put the wire back where it came from...
The length of the wire will give you a clue
A terminal point with no wire on it will give you a clue
My guess is that it's the kill switch wire which usually connects to the machine's frame - but that's just a wild guess.
You might trace the wire back to where it comes from - if it connects to the kill switch than just fasten the loose end to the chassis - anywhere will do.
Good luck...
A Ground
September 2014