The light activated switch provides a useful alternative to the traditional chain switch in operating traffic lights underground. The light switch eliminates the need for human contact with the switch mechanism. With a light switch mounted at the entrance points of the roadway under control, operators can switch the traffic system using their cap lamp. The light switch is also viable in situations where a chain switch or limit switch are not easily mounted or accessed. Additionally, the light switch has found application in hazardous areas mounted in a flameproof enclosure enabling operators to activate a PLC input inside the flameproof enclosure via a cap-lamp or torch.