Hello. I've recently have a lot of question of building Faraday cage for our high voltage gas discharge lab. I think this question is a kind of fundamental question for such a job. Let's say I would make perfect Faraday cage with perfect shielding or have metal plate of infinity transverse size. Thickness of the plate is much larger than skin depth of the AC current. Then AC current path (wire) are connected to both surface of the metal plate in a way described in attached image to try to communicate between two sides with shielding radiation EMI. I believe this is actually not conducting but just good insulation since thickness of the metal plate is much larger than current skin depth. As a result, if the current can flow, the current only can flows along the surface then...never succeed to fine a way to get inside of the shield as shield is assumed as perfect. If this is true, when we make metal enclosure of electronics and the enclosure is to be used as a current return path, it is always better to drill some hole for AC current to easily pass. Could you please confirm this is right logic?