Mooncake boxes made of metal are extremely well shielded. It is to solve the problem of insulation, the motherboard underneath and between the box to pay attention to be well insulated. You can use Styrofoam spreader board cut into the right shape and then glued to the bottom of the box with universal adhesive. It's easy and inexpensive to work with. From the photo of the power supply you can buy a quasi-system or 1U server power supply also in a box. The power cord is made into a movable jack. Just like the laptop power supply look.
It's still a good idea, and it's good for MCE.
I've had this idea for a long time, but it's not a good look. But it doesn't look good! There's an extra layer of boxes (power supply and hard disk), but it's worthwhile to take a lesson from it. We can all do DIY computers quickly, but motherboards + CPU + memory ........ Do we may have to buy such a motherboard, I do not know how to use it?