As a property owner you have the right to evict illegal tenants from your basement. You can evict tenants who fail to pay rent, tenants whose lease has ended and other people who illegally take up residence in your basement. Eviction laws vary by state, but laws in all states follow roughly the same basic process. In some instances the illegal tenants may agree to leave upon your request, but if they refuse to vacate the premises, you must abide by your state's eviction laws.
Serve notice to your tenants. The eviction process begins when you give tenants notice to quit or an eviction notice. Under state laws, illegal tenants normally have at least seven days to vacate the property after you physically hand them the eviction notice.
File an eviction motion in state court. You must provide the court with a copy of the eviction notice and you cannot start court proceedings until the period of the eviction notice has expired. The court must send a notice to the tenants, instructing them to appear in court.
Attend the court hearing and explain your reasons for evicting your tenants. If the judge rules in your favor then the court issues a judgement notice requiring the tenants to vacate your basement. Depending on your state's laws the tenants may have seven to 10 days to vacate the property.
Contact the local sheriffs department or the police and make arrangements for law enforcement officers to forcibly remove the tenants from your basement. Ask the officers to remove any property from your basement that belongs to the tenants.
You may feel inclined to remove illegal tenants yourself. However, so-called "self help" evictions are illegal in most states. You could face civil or criminal damages if you physically harm your tenants or their property while removing them. Rely on law enforcement officers to remove illegal occupants.