@Carla479 Airbnb tends to remove reviews that make explicit mentions of things such as drugs, sex, bodily functions, and illegal activity. It's legally risky for them to host content that can be legally construed as libelous. Therefore, even if you feel 100% certain that the guest was smoking weed in your place, your review should avoid direct accusations.
Examples that would make the cut:
"The home was left with an unpleasant odor and required additional airing and cleaning after this guest's stay."
"Although my house rules prohibit indoor smoking, the home was left with a strong odor and a burning candle."
But if your guest was smoking any substance in a non-smoking home, 4 stars for House Rules seems awfully generous. Sounds like a 1 star guest to me.