I designed this weight - reduced hook to be able to hold both an object you'll normally hang (a piece of clothing / keychain) and also a cloth hanger (poke the hanger through the hook holes)

To print this hook you'll need to print two halves (it's the same model, you just need to duplicate and mirror one of the pieces, after printing, glue ‘em together and, BOOM, you just got yourself a nice n’ neat wall hook.

To use it, use double sided tape and glue it on the wall

I'd suggest you to print it on PETG or ABS, PLA are only for light use, since it is a bit brittle