It ain't wire - it's stainless steel THREAD, ideal for low power and signals routing.
Conductive Stainless Steel Sewing Thread 7Ω - DFRobot
Makeronics Conductive Thread 2 Bobbins 65ft/20m
Aurifil Quilting Thread 50wt Stainless Steel
Stainless Conductive Thread (40ft.) - Creatron Inc
Conductive Stainless Steel Sewing Thread 7Ω - DFRobot
LilyPad Basics: E-Sewing - SparkFun Learn
Adafruit Stainless Thin Conductive Thread - 2 Ply - 23
Conductive Thread
JAMECO VALUEPRO 260151023534H Conductive Sewing Thread
Aurifil Cotton Mako 50wt Stainless Steel Thread Large