I did a switch swap on a mate's LP Supreme a couple of months ago and there was no shielding in the cavities.
On the subject of Faraday Cages there is a very impressive one at Garden Island in Sydney, it's the navy war room. The roof, walls & floor of the room and the long winding corridor into it are all welded steel and the only penetration for communications is optic fibre.
I don't know if it's still there or been moved it was around 1991 when we did the comms upgrades there, even if it's still there I guess what I installed is long gone because technology has come a long way since then ( but it's still all just zero's and one's )
I wouldn't be surprised if it was still there. There is a lot of stuff there, well between Garden Island and Kuttabul.
Besides we are still using 30 year old frigates...
Col.
I admit that I am an agent of Satan, however, my duties are largely ceremonial.