I currently am the sole lease holder of a two bedroom apartment in Mississippi which I listed an occupant so that they could do a background check on and so I wouldn't be breaking any rules. I agreed to let this person ( a friend from another state) stay with me as long as they had a job and were helping with the rent and utilities. She was actually fired from the job that I had lined up for her. It has been a month now and this person has not paid anything towards rent or utilities nor has even tried to find another job. She doesn't get up until noon and fritters the rest of the day away. I was contacted by my Internet provider that this person ( they actually thought it was me because it was my IP address) was downloading movies from the Internet illegally and I was threatened with some hefty fines. It was the last straw.. first I password secured my wireless Internet and told her our arrangement wasn't working and she would have to leave in 10 days. In between, my mother came to visit me and my occupant actually threatened my mother with bodily harm for asking her why she figured she deserved a free ride which set off another wave of drama. I have found out the hard way that my kindness and good deed will not go unpunished. How do I get this person out of my apartment. She is not listed as a lesse, but rather an occupant and she refuses to leave. How do you legally get someone out when there were no real terms of rent to fall back on for non payment.
What are my options?

You are her landlord and she is your tenant on a month to month basis. Do you have any proof that she paid rent at any time? If so, you can give her a pay or quit notice. If not, Mississippi law allows a one week notice in writing of termination of tenancy. (Mississippi Termination of Lease Notice Law - Lease - Landlord Tenant (http://landlordtenant.uslegal.com/lease/mississippi-termination-of-lease-notice-law/))

If she does not vacate by the deadline, then you have to go to court to evict.

Scottgem - If I can get her to agree to willfully quit tenancy in exchange for giving her a free ride back to her own state, is there any legal form or information that I must write into this agreement to allow it to stand up in court?

No, since the agreement would not stand up in court. You can make the offer. When she leaves and returns the keys, have her sign a simple statement that:
I am vacating the premises at <insert address> as of <insert date>. I have returned the keys.

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