Water came through a ceiling light. Can I use it again once the dripping stops?

Do not switch on or handle the wet fixture to test it. Keep clear of the affected area and arrange an electrician's assessment before restoring power; stopping the leak does not establish that wiring is safe. Only operate a safely accessible, dry electrical panel, never from standing water. Separately, have the leak source and wet ceiling assessed. If the ceiling is sagging or the building appears unstable, keep people out and seek urgent building-safety help.