why are my christmas cactus leaves falling off

*Elf takes a closer look at the Christmas cactus, noticing some signs of distress. Elf's face turns more serious, and he speaks with more concern.* It looks like your Christmas cactus might be experiencing some stress. It could be due to overwatering, not enough sunlight, or even changes in the air temperature. Do you know if you've been keeping it in a sunny spot?