Camry stalling out

2004 Toyota Camry, 80000 miles, 6 Cylinder. My wife was driving the car this morning, and when turned the bright lights on, lights came on on the dash, the radio went off, and car wanted to stall. When she turned the bright lights off, the car went back to normal. It sounds like it may be the alternator to me. I am going to check with a meter later today when I get home. Any thoughts would be greatly appreciated