Absorption of digital hash

I used my golden plate homemade device : a plate of shungite with an external copper tape face + in some case mineral as quartz to fine tune the sound...😊

I used mostly  very thin plate unlike the example of this image

Thanks guys. I've found Holland Sheilding System as a result of your helpful comments. Now will do some shopping :)

OP:  Not sure what you are doing, but please keep in mind the heat dissipation of some devices.  Wifi routers especially need a lot of airflow to function at top speeds, and may even shut down.  Modern, Energy Star compliant Ethernet switches should be fine though. 

@erik_squires . Like to improve my Oppo 205 without any upgrades. Just read about Berkeley as I'm considering dac upgrade ( or Spectral spinner). Still love disc movies on my Sony 4k. Mu metal for transformer 'may' be interesting. I'm just getting back to listening. Been busy w project. Relaxation coming up-again :)  Time to ponder hi-fi improvements. Your comments always interesting/informative/ mannerly :)

Just be aware that proper EMI/RFI interference shielding requires significant engineering knowledge and it is best done by professionals and requires very expensive specialist equipment. I see little point in trying ad-hoc solutions, it is very difficult to achieve a good shield at home. Do you really have a EMI/RFI radiation issue and how does it manifest itself?