Greetings! This is a shelf with key hooks that works with the widely available emergency battery powered LED light shown.
No supports, print with fan on high.
In the included picture I printed with zero top layers just for effect as I liked the exposed infill look but obviously just add top solid fill layers to cover infill if desired. I used 3 perimeter shells.
It is made with a good bit of clearance to accommodate different printer tolerances. If your printer is highly accurate you may want to scale down slightly or add tape around outside of light for tighter fit.
I used strong velcro applied to back of light to attach to wall so it could be removed easily to change batteries in the future. Batteries should last a very long time though, since the light is only used during power outage.