Yes a metal cage of conducting metal such as copper for example shouldf help block the unwanted signal. The cage is called a Farraday cage, I think.
CB Radio interference
Hey ya'll, im livin' in brooklyn NY. Anybody ever get dudes talking on CB radio coming through the phono amp? always at about 6pm im playing tunes on the TT and i get a faint conversation in CB code over laying my music! anyone else in a metropolis ever get this and if so, is there a solution other than not listening to Lp's a 6pm + or - an hour?