Cable management box
If you have a mount for your TV, fasten all of the electronics with the unsightly wires to it. (If you need to, build a small lightweight frame to attach to your mount.) Bundle up the wires as much as possible before fastening them to the mount so they don't get tangled once they're up there. Use bungee cords to secure heavier hardware like a cable box or router. Plug everything into a power strip so you only have to worry about one wire running from your TV to the wall.