This is modelled after a hook on a baby gate. I made it to replace the original after it broke. It has holes on it to mount it to a wall in two different orientations.
I'd suggest printing it laying flat with supports on for the overhang (I never tested printing without supports). High infill is good as well to ensure strength. I went with 50% infill and it's currently holding really strong.
Gate_Hook_v3.stl | 119.5KB |