Lights aren't working, but outlets are fine and breaker hasn't tripped?

If all outlets work but multiple lights in one area stopped working with no breaker tripped, the most common cause is a loose neutral or loose connection in the lighting circuit. This often happens in an addition where several lights are daisy-chained together. Possible causes: 1. Loose neutral wire in a junction box or light fixture (very common). 2. Backstabbed connections on switches or light boxes that finally let go. 3. A hidden junction box in the addition with a loose wirenut. 4. Shared circuit split where the lighting branch lost continuity even though the breaker is on. Since outlets work, the issue is almost certainly upstream on the lighting run, not the panel. How to fix: A licensed electrician will need to open the first light or switch box in the chain and check for a loose neutral/hot connection. Once the bad connection is tightened or repaired, all lights typically come back on.