Try a Vet as in animal doctor rather than someone trained to kill or go to the pet market in Xinkai Liu. If you end up with a spray then fleas love carpets and typically hang out where a table or chair leg meets the floor or along the skirting.
But treating the house is not enough because you still need to treat the cat. Last I heard the best way to treat a cat for fleas was still systemically – that also requires a spray – typically by spraying the cat along the spine but a different spray (e.g. frontline) from the one you use on the floor. If you cannot get a systemic spray which will provide a deathzone for fleas on your cat for about 3 months (I think) then with a conventional spray you should treat the cat and also your floor area about every 10 days until you have eliminated the problem. However, if your cat has free access to the outside world then you should be prepared to expect infestations as soon your cat encounters a mouse, bird or another cat.