Hey Osgeld! XD
Ok, this is not for a board or breadboard.
What I actually want to do is to "tap" an already existing 24 AWG line on the wiring side of my model R.R. to derive a sense connection (pulled to ground) to my Mega2540 inputs in the shortest/easiest possible way.
See the wires already go from the train layout control panel momentary pushbuttons to the turnout double-solenoid machines. I don't want to strip the wire and just tap it there by wrapping another wire to it in order to keep distance to the MEGA short. So, I was thinking of these Quick Splice connects to do it in a better way. 
Thanx!!!!