Here is the original: https://www.thingiverse.com/thing:2988576

The switch lever has two positions, when you push the switch it snaps into its new position by flexing the thin walled sections. If you push the switch back down it snaps into its original position. I have also added a small hole to fit a keychain.

A contact force is created by causing the contacts to connect before the second stable equilibrium position is reached. Living hinges are used in the 3 joints. 

Print Settings

Layer Height: 0.2mm

Nozzle Diameter: 0.4mm

Infill: 20%

Material: I used PLA+, 

Note: It can be brittle depending on  print settings and material used. I recommend to actuate it once (very carefully) after printing while the fidget toy is still warm to bend the mechanism in. In my experience these mechanisms are quite sturdy, depending on printer settings and filament. Let me know if it does not work for you, leave a comment and i can try solve it.