Is it permissible to pay a sum of money to a municipal inspector in exchange for him averting his harm from me and avoiding electricity disconnection and fines, knowing that this is a building violation I committed following the example of my neighbors?

If the violation was applied rightfully, without injustice, then it is not permissible to pay money to the employee to cancel it, otherwise it would be a prohibited bribe. As for the harm incurred by the questioner, it requires consultation with scholars to assess the extent of necessity. The limit of necessity is that which entails fear of perishing, or extreme hardship, or the inability to achieve a minimum standard of living, as Wahbah Al-Zuhaili defined it: a danger or severe hardship that causes fear of harm to oneself or one's property, thus making it permissible to commit a prohibited act to avert harm.