This bracket will allow insertion of rectangular rocker switches and has an opening of 20mm X 12.5mm.

Orient with the large opening on the build plate and most printers can print without any supports. The only overhangs will be the 2 screw holes and if it isn't perfect, it doesn't really matter since you're going to run a screw through it anyway.

Parametric file is shared with my OnShape account at:

[https://cad.onshape.com/documents/1ae170da408162fbca4c3d64/w/a0f05f8f0ec422b149ff7b02/e/b1ce148cd51bdc548ae8ab79?renderMode=0&uiState=633b8f44197c9627417a7d04](https://cad.onshape.com/documents/1ae170da408162fbca4c3d64/w/a0f05f8f0ec422b149ff7b02/e/b1ce148cd51bdc548ae8ab79?renderMode=0&uiState=633b8f44197c9627417a7d04)

The switches I used were from this link:

[https://www.amazon.com/dp/B082PQQ8K3?ref=ppx_yo2ov_dt_b_product_details&th=1](https://www.amazon.com/dp/B082PQQ8K3?ref=ppx_yo2ov_dt_b_product_details&th=1)