What is the ruling on brokering the sale of places where evil acts may occur (such as commercial complexes where there is mixing of genders, or an internet cafe, or beachfront chalets), and what is the ruling on the money earned from this brokerage?

Islam has forbidden assisting in haram (unlawful acts) because the one who assists is a participant in its propagation, relying on the Almighty's saying: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression," and on prophetic hadiths that curse those who deal in usury and alcohol, and those who assist them. Ibn Hajar Al-Haytami mentioned that selling something when it is known that the buyer will commit a sin with it is forbidden, because non-Muslims are addressed by the branches of Islamic law. Therefore, it is not permissible to mediate in places where evil acts are known or suspected to occur, unless the matter is merely a doubt or an illusion.