We have measured the temperature dependence of the β-NMR resonances of 8Li implanted in thin films of Au and Ag. At room temperature single narrow resonances are observed. The absence of appreciable quadrupolar splitting or broadening indicates that the Li is isolated and at a site of cubic symmetry. As the temperature is lowered, a second resonance appears which is shifted higher in frequency by ∼100 ppm. We attribute the two lines to two distinct cubic sites with slightly different Knight shifts and discuss the application of this result to study fundamental phenomena exhibited by nano-confined metallic electrons.