Unknown Man Leading Prayer
Interpreters mention that if a dreamer sees an unknown man leading people in prayer in a mosque, and the actual imam of that mosque is ill, it might indicate the death of the sick imam.
Per Ibn Sirin's Muntakhab al-Kalam fi Tafsir al-Ahlam
Note: These are traditional scholarly interpretations (ijtihad) drawn from a specific classical source — not a binding religious ruling, fortune-telling, or a prediction of the future.