This thing was anchored to the walls. Close to the left 2 wires you can see at least one anchor, standArd type. Drill round hole into masonry wall, insert anchor. When Screw is tightened, anchor expands and presses against the wall. The cable looks like standard NYM cable and the device was probably an all-in-one surface mount device. You're allowed to staple this cable to the wall surface, so this installation method is very common in renovations (My old room had all receptacles wired like that, I didn't want to rip up the walls).
>These are usually wired into zip-cord stapled to the walls (dangerous)
Well, as long as the 16 AWG zip cord is fused @ 10A... [Linked Image]