Here is an example of how to bless a home. If it is not your home you need to receive permission from the owner or the person who has stewardship over the property.
Before giving the blessing pray to know whether the spirits are lost disembodied spirits or dark spirits from the pre-mortal world, because it may give you some insights as to what is going on. Ask if there is anything specific the Lord would have you to do in this home blessing. You may be told to disregard the entire cleansing as it is described below and follow a personal revelation. Remember to be humble and Christ-like as you perform the blessing.
Standing in the room with your arm raised to the square . . .
“I________having received permission of__________by the authority of the Holy priesthood and as a servant of Jesus Christ, I command that a spiritual cleansing take place over this property of which I am steward and have dominion over.
I command that an Eternal Flame start from the property boundary on the North and extend from the far East and West boundary on the sides and move over the entire property to the South and as it does it will sweep out every unwanted spiritual presence, every marking, device, residues, and seal up every portal which is used to bring harm to this family. This cleanse will begin now. (Pause and wait for the flame to move across the property. See it in your mind.)
Ask the woman of the house if it is thorough or if there is a particular place that needs further cleansing. Did we get everything? (You are the transmitter, she is the receiver.)
In the name of Jesus Christ, I command that Angels of the most high, soldiers of Light from the other side, escort the lost spirits off the property. Or if it is a Dark spirit from the pre-mortal world, I command that it be assigned , bound and shackled and sent to the eternal prison.
I command that shields be placed, starting at the corners of the property and extend over the top from above and beneath the foundation from below. That no unlawful spirit or evil intending person will be able to pass this barrier.”
Pronounce a blessing as guided by the Spirit…(Be sure to be as detailed as possible, blessing every individual item to fulfill its purpose. Ie, bless the foundation, the walls, the plumbing, the heating, the ducts, the electronics, everything you feel inspired to mention.)
End in the name of Jesus Christ. Remember, a home blessing is not permanent. It is like spraying for bugs. You do a full cleaning and from time to time you have to spray bugs here and there. Eventually you need to do a full cleaning again. I hope this helps.