A Parametric & Stackable Keyboard Switch holder. I've tested this holder with three switches and they all fit perfectly (best to use a switch puller to get them out - but it also means they won't accidentally come out).

Print Settings:

• I printed on Stock P1S
• No supports needed
• Holder: Print with stacking lip up (this gives best surface finish to the part for the switch)
• Lid: Print with stacking lip up
• 2 walls

10x11 (110 switches): ~216g, 7h

If you need a different size, let me know and I'll upload a new one. 
Available Sizes in STL:

10x12
10x11

9x9

5x5

3x3