I shielded two of my guitars with copper tape.... control cavities and pickguards. It does work, but it's not going to make a single coil into a humbucker. There is still noise there, which is disappointing at first (you expect after this big taping job that all the noise will be gone). But if you compare recordings between the pre-shielded and post-shielded guitar, the difference is noticeable and significant.