Screw in power switch housing and mounting bracket

This is a box for my power switch (with screw holes) which I designed to be screwed to the leg of an Ikea lack table. I have an Anet A8 and wanted a power switch to be available near the front of my work area, whilst hiding the PSU under the table.

This housing accommodates a screw-in power switch (non rectangle) approx 49mm x 58mm (inner rect is 27mm x 46mm).

The power box fixes to the box using some self-tapping pan-head M3 screws.

To fit the mounting bracket accurately, insert some s