If downlights are not correctly installed or maintained they can set fire to insulation, wiring, leaf litter or timber which can burn undetected in the roof space above smoke alarms.Old or poorly installed ceiling downlights are thought to cause at leat one house fire a week in Western Australia.f downlights are not correctly installed or maintained they can set fire to insulation, wiring, leaf litter or timber which can burn undetected in the roof space above smoke alarms.