Could a technician be seriously injured or killed from working on a 120V lightning circuit with 100W bulbs?

Yes, a technician could be seriously injured or killed while working on a 120V lighting circuit, even with 100W bulbs. The voltage poses a significant risk of electric shock, which can lead to severe injuries or fatalities. Additionally, if proper safety precautions and protective equipment are not used, the risk increases significantly. It's crucial for technicians to follow safety protocols when working with electrical circuits.