The new smart meters that our electrical utility company installed on my house sends out powerful "WiFi" signals in bursts. I am concerned about the long-term health effects of these microwaves and so I decided to make a shield to stop them. Now, as you may know, the whole reason they installed it (in the short -term, anyway) is to be able to read my monthly use remotely so they could lay off an army of meter-readers. I have an issue with that too, but I have no shield for their jobs. Blocking the transmissions of data will force them to come out to read it manually anyway. Too bad: Nobody asked ME if they could put a powerful transmitter on my house, so they will have to deal.
Here's how: Aluminum window screen, available at most hardware stores, TOTALY blocks this type of microwave radiation. A single layer is enough. One could simply tape a big piece over the whole thing, but I wanted something more user-friendly and more long-lived. First, wear some leather gloves. This material is hazardous and WILL poke your hands but GOOD countless times if you don't ! I used sheet metal shears to cut it, but some good heavy kitchen shears will work. You may find them more dull afterward though. It's pretty easy to cut. I used a hot glue gun with clear sticks to bond the base to the cylinder, and shown in the photos. I used some small aluminum pop-rivets to attach the sign, and nylon thread (waxed) to attach the "lid".
I bought about 4' x 3' off of a roll, and cut the piece that the base would be made from. I designed it to be double-thickness for stability and durability. Just cut about 14" x 28", fold it in half and then fold about 1" over itself on the edges to thicken it.
Then mark and cut a round hole in the center of that square that is 1" SMALLER than the cylinder you need to enclose the meter.