After upgrading my soldering iron I still wanted to keep the old one for installing heat-inserts in 3d prints. As the “base station” takes up quite some space, I removed the electronics (no big deal) and put them into this small controller box. Lid is a tight fit and can additionally be fastened with short M2 screws.
Take care when rejoining the wires from the power switch, as you're dealing with mains voltage (but I assume you are aware of that when you're modifying your soldering iron).
The author marked this model as their own original creation.