When is it necessary to use insulated staples? I bought a bunch of plain metal staples for wiring my garage with 12/2 and plan on leaving the walls open. There will be four 12/2 wire leaving/entering the switch box, can I use regular staples and staple two pair of wires side by side up the stud or do I need something else like stacker staples?
Another option is to run 1 set down the middle and ty-wrap the 2nd set to the staple holding the 1st set. Do not just ty-wrap to the cables to cables because that is not totally legal. Cables may support cables.