22 Ga Tinned wire is standard. [URL]   [URL]  
I have swapped out my Optiplex 9020 MT's Motherboard into an extra large ATX case, & after installing everything  else I want, am down to having to do a splice & butt-connection of the power button wire from the motherboard for it to extend & reach the power button; what specified wire is needed to make this work?
Type Of Wire Needed For Butt-Connected Extension of an Optiplex 9020 Power 
Button