This is a wall switch plate replacement designed for the disabled in mind.  The colors were chosen to be easily seen by someone with color blindness and glow in the dark filament was used for the knob.  It's printed in place as an object with multiple parts.  This switch was printed from all PLA, however, PETG would give better strength and durability.  If you do use PETG for the base plate use it for the On and Off also for good adhesion.  The knob could still be printed from PLA as a lack of adhesion is advantageous for this part.  You can use what you like for perimeters, layers and infill.  Supports on the build plate only were used.