Light does not always increase safety. In at least one case, reviewed by Barghini and Medeiros*, insects attracted to lights caused disease in humans. A sugar cane kiosk in Brazil attracted Triatoma tibiamaculata, true bugs that are vectors of Chagas disease. The bugs made their way into the sugar cane being pressed to make drinks. Pressing the bugs released the Chagas trypanosome into the sugar cane liquid. Twelve people who consumed the sugar cane drink were infected with Chagas disease.
Entomologists are interested in insect orientation to lights and the relative attractiveness of different sources of light.
*Alessandro Barghini and Bruno A. S. de Medeiros. 2010. Artificial Lighting as a Vector Attractant and Cause of Disease Diffusion. Environ Health Perspect. 118: 1503–1506.