 The gauge of wire used, current rating of the fuse (if present) and the power consumption of each string will determine how many strings can be safely daisy-chained this way, or whether the end string will have diminished voltage and brightness.The number of strands of continuous light sets that may be safely daisy-chained in sequence varies based on whether the lights are LEDs, ordinary miniature light bulbs, or the larger C7/C9 type light bulbs.Other factors include the voltage of the set and the size of the wiring in the set.