We report a flexible self-standing paper-composite made from a (semi)conducting polymer - namely, PEDOT:PSS - and nanofibrillated cellulose. The material exhibits excellent mechanical and electrical characteristics. It is also inherently self-adhesive which enables the material to be laminated and delaminated at will. This modular property opens the door for a plethora of applications where reconfigurability and ease-of-manufacturing are of prime importance. The PEDOT:PSS paper composite acts as an active substrate and, thanks to a good bulk conductivity, may carry large currents (> 1 A). In turn, this enables the material to be used in a variety of power electronics applications. The fabrication process is fully scalable in the x-, y-, and z-, and, surprisingly, has a thickness-independent conductivity (> 130 S/cm). We use it to demonstrate an electrochemical transistor with giant transconductance (> 1 S), a tunable electromagnet (> 1 G), and a high capacity supercapacitor (> 1 F). We also construct wires and coaxial cables with it, and propose that PEDOT:PSS composites might (post copper-peak) reasonably be viewed as suitable and sustainable replacements for Cu.