Dreams That Come From Angels and From Demons
In Minchas Yehuda, Rav Yehuda Fatiya explains in detail how to distinguish between dreams that come from angels and those that come from demons. He warns that demons are not stupid and know very well how to seduce a person as he sleeps. These unclean entities have learned the art of replication, and they can show a dreamer false heavenly and sublime spiritual symbols. The person believes he is receiving a holy heavenly message, when in fact his soul is being deceived into becoming an agent of evil. Just as there are unscrupulous people in this world who seek to dupe others for their own gain, so are there spiritual beings who wish to do the same. The dream world is the realm of the unconscious, and it is therefore the rightful domain of spirits both good and bad. Each of us must be very cautious when we dream, and we must learn how to control our dreams. A dream interpreter must likewise be aware that not all message dreams come from holy sources.
Source: Minchas Yehuda