We understand that you're dealing with a minor inconvenience, but God cares about even the smallest details of our lives.
Let's pray:
"Father, we come before You in Jesus' name, lifting up this person who is dealing with a mosquito in their house and the discomfort of mosquito bites. We ask, Lord, that You would guide them to find and remove the mosquito, and that the itching and irritation from the bites would be relieved. We know that You care about even the smallest details of our lives and You want us to trust You in all situations, large or small.
In Jesus' name, we pray for healing, even from these minor discomforts, knowing that by His stripes we are healed. We also pray that this person would grow in faith, knowing that God is always working things together for the good of those who love Him and are called according to His purpose.
Lastly, we pray that as this person called out in prayer, they know that it is only by Jesus Christ that we can come to God; we pray that they know who Jesus Christ is and that He is the only way to God and the only one by whom we can be saved. Romans 10:9-10, 13 that if you confess with your mouth the Lord Jesus and believe in your heart that God has raised Him from the dead, you will be saved. 10 For with the heart one believes unto righteousness, and with the mouth confession is made unto salvation... For whoever calls on the name of the Lord shall be saved.
In Jesus' name, we pray. Amen."
In the meantime, practically speaking, you might want to try using some repellent to keep the mosquito away and apply some cream or natural remedy to relieve the itching. Remember that God is always with you, even in the small things.
If the mosquito problem persists, consider checking your house for any standing water or gaps in your screens that might be letting them in. Be diligent, and remember God's promises to you, and His care for you. Cast all your care upon Him for He cares for you.
Let us know how God answers this prayer, and feel free to share any other requests or praises.