The key in shielding is to surround whatever you wand shielded with a conductor. EM waves don't penatrate conductors very well. I'm not even sure you need to ground it, but it is a good idea for other reasons if not this one (unless you like getting electicuted). As a previous post mentioned, the smallest opening should be smaller than the wavelength of the EM radiation, in this case a few cm should do it.
Take a look at your mocrowave door sometime. It uses the same idea. THere is nothing special about the glass, it just has a piece of metal with small holes in it. The EM (microwave) frequency is about 2.5 GHz IIRC. Those little holes are smaller than that wavelength, so nothing gets through.
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The key in shielding is to surround whatever you wand shielded with a conductor. EM waves don't penatrate conductors very well. I'm not even sure you need to ground it, but it is a good idea for other reasons if not this one (unless you like getting electicuted). As a previous post mentioned, the smallest opening should be smaller than the wavelength of the EM radiation, in this case a few cm should do it.
Take a look at your mocrowave door sometime. It uses the same idea. THere is nothing special about the glass, it just has a piece of metal with small holes in it. The EM (microwave) frequency is about 2.5 GHz IIRC. Those little holes are smaller than that wavelength, so nothing gets through.