This is a simple frame with key hanger that installs around light switches without permenant solutions. In the main print profile I have included two versions. One can hold 3 keys and the other 4.

PETG might work better since you need to flex the model a little bit to get in place. However, I printed it in PLA and it still worked pretty good. Just be careful of not bending the model too much and deforming it.

The Fusion 360 file is configurable with 3 parameters: number of pegs, width, and height. I suspect you could make minor changes within your slicer to modify the size as well.

Happy printing!