I want someone to remove themselves from my apartment who is not listed on my lease. What should I do?

I'm going to assume that you are the tenant and have a lease with the landlord of the apartment, and that you allowed someone to move in with you but did not have them listed on the lease as a tenant. I'm also going to assume that you allowed them to live there long enough to establish residency, such as receiving mail at that address.

If that's the case then you have sublet part of the apartment to them. That makes you the sublandlord and they are the subtenant even though there is no lease agreement. If you want them to leave you have to give them a written notice that their tenancy is terminated and they must move out within x days. The number of days depends on the law of the state where the apartment is located. Tell us which state and we'll tell you the correct number of days.

If they haven't moved out within that time then you have to file a lawsuit for eviction. The court will schedule a hearing, you'll testify that you terminated their tenancy and provide a copy of the notice you gave them and the court should grant you a judgment for possession. Then you can make arrangements with the sheriff or constable to perform the eviction.

If I've assumed anything incorrectly, tell us your situation and we'll tell you what you need to do.

Agreed, you have allowed this person to achieve residency so they must be evicted like a teant if they won't go after simple asking him to leave

Without any information it is hard to say, do you live in India or China or the US.
Laws vary greatly.

In the US laws vary by state.

Next who is the person, a boyfriend, your child, your spouse? Example even if not on the lease a spouse will have other rights.

So if you want to give us more info, we will be gald to help

I am very nervous and don't know how to handle the situation Im in. I met a man several years ago when I was separating from a 18 year marriage. The guy seemed nice (I was distracted with my own problems to notice his true self). Since then he has done horrible things mental, physically to me. At this point & time I have a apartment with just me and my 17 year old son on the lease in Jax FL, I work 2 jobs and Im hardly home. My ex boyfriend has been staying with me and I let him get his food stamps at my address recently so now the other night I came home after working 12 hours and he was drunk calling me really foul names in front of my son and telling me he isn't going to leave my apartment cause he can show mail in his name and he isn't going to pay anything (not that he ever would cause he doesn't work and he collects a mental disability check). My son is scared and so am I, he makes horrible threats of hurting us. Oh and over these several years Ive known him he has been arrested twice for abuse on me but during thecourt process somehow convinced me to not follow up and show up for court against him so the charges got dropped. He appartently has lived this way according to his family that recently contacted my to warn me he is a professional con man, he finds women that are vanrable and pretends to like them and talks them into letting him get a piece of mail at their home then he goes for the swatting.