I want to file a lawsuit against a company who cleaned out my parents house BY MISTAKE as they should have cleaned out the house next door.

Your mother has a right to bring an action against the company that did the work as well as the company that hired them to clean out the home.  If you have a power of attorney, you may be able to file suit on behalf of your mother.  Your mother can recover both the value of the goods that were taken out of the house   ( personal items and furniture ) and any loss in value to the home caused by the removal of items which are not personal items, such as carpet.  One concern will be how to document what was in the home at the time it was cleaned out.  Hopefully, you and other family members will have photos or other documents to prove what was in the home.  I suggest you consult with a lawyer about the power of attorney issue and how to file suit - since your case will not qualify for the small claims court.   This answer is given in accordance with the laws of Virginia, and is based on the facts that are recited, and assumptions which may or may not be accurate. Accordingly, this response may not be relied upon and may not be applicable in any other state. It should not be relied on as legal advice, as that would require a detailed analysis of all of the facts involved in a specific case, not just the limited facts presented in the question.