D-Line Cable Trunking, Wire Cover for Wall, TV Cable Tidy, Self-Adhesive, Hinged One-Piece Design - Magnolia, 60 Mm (W) X 15 Mm (H) X 40 Cm Length. Hide Wall Mounted TV Cables: D-Line TV Cable Cover, 60mm (W) x 15mm (H) is designed to fit flat on your wall, providing a discreet solution for hiding TV wires on walls.
eBay