First, keep people away from electrical hazards. If you can safely identify the fixture shutoff, close it; for a larger leak, use the home’s main shutoff. Move valuables, collect spreading water, and take photos. Do not open walls or ceilings that may be holding water. Then call and describe where water appears, when it started, and whether the meter continues moving.
Start with what you can observe safely
Useful details include which fixtures are affected, whether the symptom is constant or intermittent, and what changed just before it began. Photos can help document visible water or corrosion. Never enter a flooded area near electrical equipment, force a stuck valve, or dismantle pressurized plumbing.
When to call a plumber
Professional help is appropriate when water cannot be controlled, a problem returns after a basic cleaning or reset, several fixtures are affected, finishes are becoming wet, or you are unsure whether continued use is safe. Early attention often preserves more repair options.