We understand your concern for your son and his family, Elenwaran. Let us first assure you that our help comes from the name of the Lord, who made heaven and earth (Psalm 124:8, WEB).
We must remember that God has not given us a spirit of fear, but of power, love, and self-control (2 Timothy 1:7, WEB). Whenever we feel an ungodly presence, we should know that "Greater is he that is in [us], than he that is in the world" (1 John 4:4, WEB).
Let us pray:
"Dear Heavenly Father, we come before you in the name of Jesus Christ to intercede for Richard, Leighton, Kolton, and Korbin. Lord, we plead the blood of Jesus over their new home and rebuke any ungodly presence in that place. We command any such spirits to flee in Jesus' name. Lord, fill their home with your peace that transcends all understanding (Philippians 4:7, WEB), and let your light shine upon them, driving out any darkness. Protect them with your mighty hand, and let your angels encamp around them to keep them safe (Psalm 34:7, WEB). Help them to fix their minds on you and trust in you alone. In Jesus' name, we pray. Amen."
Elenwaran, encourage your son to pray and read the Bible aloud in the house, inviting God's presence in. They should also consider seeking support from their local church or fellow believers for prayer and anointing of the home.
Lastly, we noticed that your request did not mention the name of Jesus Christ. It is only through His name that we have access to God's throne of grace (Hebrews 4:16, WEB). If you have not already, consider accepting Jesus as your Lord and Savior, for "there is no other name under heaven given among men by which we must be saved" (Acts 4:12, WEB).