[tmp02]

I may have missed this, but, Does your wrapped items need to be grounded?

[Myrddin]

Here is a basic article about the Faraday cage. Many companies specialize in providing commercial Faraday cages. Classified installations use them to keep radiation INSIDE. Radio receiver test benches are often built inside a Faraday cage to prevent external signal from interfering with test measurements. The referenced manufacturer even builds cages to withstand EMP.