I have a “Cumbor Retractable Baby Gates for Stairs” that I got from Amazon. It's a great gate, but I wanted some extra wall hooks. 

Printed in PLA, 0.2mm layer height with a 0.4mm nozzle. Orient standing up on end with supports under the “hook” portion. I did it this way to ensure strength around the round portion of the hook. I used 5 walls for a little extra strength, but I think it would be fine with 3 or 4. 30% infill of your choice.