the only point of the light is to add a small amount of heat with very little electric output- an incandescent would work fine too but might get TOO warm. Anywhere not in contact with the buds or box will do. That small amount of light is insignificant; direct sunlight is too much and may break down your psychoactives, but a CFL won't do squat.
Check the humidity in the box and make sure it's below 50%.