The item that I measured with calipers was a simple one-gang switch wallplate. On Thingiverse, I came across an addon cover for a switch wallplate that prevents the switch from being used. I used that STL file as a template and made an addon cover that simply keeps goes around the switch to make it a more deliberate action. I have a habit of hitting(turning on) switches when I enter a room, and quite often these switches are not connected to lights, but are already on and connected to running machines.

My lightswitch at home

Wallplate Cover from Thingiverse

Overlay of the Thingiverse wallplate in Rhino:

Wallplate Cover in Rhino:

3D printed Wallplate Switch Cover made on Makerbot Replicator 2 placed on a switch wallplate: