— By David Goodwin — Should I retrofit my sign with LED lights? The commercial sign market has experienced a watershed shift in the use of one of a sign’s crucial components. Fluorescent bulbs long were the favored technology for giving signs their glow, but LED bulbs have emerged in recent years as a preferred choice for many sign-makers and their customers. Newly fabricated signs now often are installed with LED bulbs. In addition, shopping center operators and others increasingly are weighing the value of retrofitting their existing …