Afternoon- I live in a townhouse, the walls I need to hide wire in either A.) are an external wall that has insulation or B.) a shared wall with a fire barrier. Basically, both are impossible to fish wire through. My idea (and it may not be original) is to take a razor, cut incisions in the drywall that are just wide enough to fit the speaker wire in it and then add spackling over the wire and paint the walls. Has anyone done this? Think it will be very noticeable? Any tips or tricks? FYI- It is a tiled floor, I cannot hide it along baseboards with carpet.