Most cacti want to rest in the winter so they can bloom the following year. Shorter days, cooler nights, drier soil is what they want. I keep most of mine under lights all winter, I just shorten their day-length, like Jiffymouse said, and cut back on the water. In general, most succulents
are the same. There are, however, some strict winter-growers. They want the same daylight, temp changes as summer-growers, but they want to dry out in the summer and get watered in the winter. I have a few aloe that like it this way, an aeonium, and a few odd others that wait for the brutal summers to pass and the winter rains to come. One's an othonna, whose genetic origin is southern Africa, and it just won't switch round up here.