Tearing a Curtain
Scholars have said that if one dreams of tearing a known curtain on a known door, it may indicate that they are slandering the honor of the curtain's owner. The same interpretation applies if a dog tears a garment off its owner, signifying slander. However, if the curtain is unknown, it may indicate salvation from a frightening matter, as an unknown curtain symbolizes evil and fear, and tearing it signifies the owner's escape.
Per Ibn Sirin's Muntakhab al-Kalam fi Tafsir al-Ahlam