A useful mechanism for people who own small pets that keep on jumping on the PC case potentially clicking the power button and turning the computer off.

Printed on a Creality Ender 3. 
 

Instructions 
 

Just use a wooden skewer for kebab to insert it through all holes of both designs, holding them together. Or use the 3d printer pin.

Designed for 3mm skewer, thought it may require some sanding if the fit is too tight.

You can then put double sided tape on one side and stick it on your case.