Dear Action Line: We have a fluorescent light in our closet, and it has gone out. How does one tell if it is loose or "blown"? If it has to be replaced, how does one dispose of the old one ...

The bulbs come on quickly; their light is bright, white, steady, and silent; and the old U-shaped tubes–they looked like bulbs from a World War II submarine–have mostly been replaced by the swirl.