GoKawiilResearcher tests decades-old TSCM claim that fluorescent lamps can eavesdrop on conversations
A blog post from a former technical surveillance countermeasures practitioner examines a long-circulated claim from spy-hunting training: that fluorescent tubes can passively pick up room audio through subtle light fluctuations caused by sound waves. The author lays out the physical reasoning behind the theory, then flags reasons for skepticism, including the near-vacuum gas pressure inside tubes and the phosphor coating's afterglow properties, both of which would work against capturing sound accurately.