Fire and safety authorities are alarmed at the increasing number of serious house fires from faulty downlights.
They say thousands of WA homes are at risk and someone could be killed.
WA's energy safety watchdog said it was investigating several fires in which properties were damaged or destroyed after downlights sparked fires in roof spaces.
The incidents, which the Fire and Emergency Services Authority said happened on average once a week, are believed to be linked sometimes to dodgy installations by electricians.
Investigators are also looking at whether the insulation industry played a part in some fires amid suspicions workers were carelessly covering light fittings.
It comes amid evidence the lights, which are hugely popular with householders and shopkeepers, can heat up to 300C and cause combustible material such as roof beams or dust to catch alight.
Electricity watchdog EnergySafety said the lights of most concern were a type called dichroic halogen globes, which are typically cheap and favoured by consumers for their attractive light.
FESA's fire investigation manager Brynn Weir said downlights should not pose a fire risk if they were installed correctly and checked regularly.
However, old or poorly installed lights were particularly dangerous because they could easily ignite combustible material, including insulation, leaf litter, wiring or roof timbers.
The risk the lights posed was heightened by the fact that any fire they sparked tended to burn in a building's roof cavity above smoke alarms.
Mr Weir said there were a few basic steps a householder could take to ensure their downlights were safe.
These included using a licensed electrical contractor, ensuring a non-combustible barrier was installed to separate lights from flammable material and making sure lights were free from insulation and combustible matter.
People should also consider replacing 12-volt halogen globes with LED globes that produced considerably less heat.
It is understood incoming mandatory energy ratings for new dwellings will reduce the risk of downlight fires by phasing out inefficient globes.