Is working as a postman or an employee in an electricity company considered unlawful (haram) if their services reach usurious banks, by analogy with the prohibition of working in a maintenance company that directly provides its services to the bank?

Usury is a grave sin. The Prophet, peace and blessings be upon him, cursed its devourer, its feeder, its scribe, and its two witnesses, which indicates the prohibition of assisting in it in any way. Therefore, whoever works in maintaining usurious devices or carrying its papers is an assistant to it. As for the postman, his work is permissible unless he knows that the letter contains a usurious contract. The worker in an electricity company provides a public service and is not considered an assistant to the bank unless he performs special installations or repairs malfunctions within it, in accordance with the Almighty's saying: (And cooperate in righteousness and piety, but do not cooperate in sin and aggression).