It is a right and biblical thing to ask God to bring His guidance where there has been wild and disrespectful behavior. That verse in Proverbs tells the truth plainly. When people do not receive and obey what God has said, their lives become unrestrained and chaotic, but there is joy for the one who walks according to His word.
That is why your prayer for your former landlord is so needed. What he and those around him most need is not simply to become more polite or respectful, but to be changed at the deepest level. The Bible speaks of two kinds of peace. First there is peace with God, and then there is the peace of God in daily life.
Peace with God can only come through Jesus Christ. By nature we are at war with God and separated from Him, but God has offered a peace treaty through the blood of Jesus on the cross. When a person turns to Christ and receives forgiveness, the war is over. He is no longer running from God or fighting against Him. Until that happens, Scripture says there is no real peace for the one who continues in rebellion. He remains like a troubled sea, restless and without rest. But God holds out the offer of peace to those who are near and to those who are far off, and He promises to heal and forgive all who come to Him through Jesus. That is what we should ask for your former landlord, that God would draw him to see his need, to submit to Christ, and to receive that forgiveness and new life.
Then there is the peace of God that guards the heart and mind. The prophet Isaiah says God will keep in perfect peace the one whose mind is stayed on Him, because that person trusts in Him. Jesus told His disciples, my peace I give to you, not as the world gives. The world cannot understand or give this peace because it depends on circumstances. The peace Christ gives remains even when the world around us is full of turmoil and strife. It comes as we keep our thoughts and trust fixed on Him, believing that He will take care of what concerns us.
God wants this peace for people. His thoughts toward us are thoughts of peace and not of evil, to give hope. He has not forgotten you in this difficult situation with your former landlord, even when the trouble feels overwhelming.
So let us pray together in Jesus name. Father, we bring this former landlord and the people around him before You. You see the wild and disrespectful actions and the trouble that has been caused. We ask that You would work in his heart, that he would humble himself before You, accept Your divine guidance, and come to know peace with You through the blood of Jesus Christ. Bring him to repentance and to obedience to Your word, that his life would no longer be unrestrained but joyful in following You. We also pray for Your perfect peace to fill the heart of the one who has been hurt by this situation. Keep his mind stayed on You and guard him with the peace that passes all understanding. Help him to sow peace even in this conflict, trusting You to bring forth the fruit of righteousness. We ask this in the name of Jesus, who is our peace. Amen.