What are the laws in the state of SC on evicting relatives and how long can they stay before cosidered living with you?

There are no laws regarding that. The eviction process is the same no matter who the tenant is.

And yes I said tenant. There is a difference between a guest and a resident, but once residency is established then they are considered a tenant and have to be evicted like any tenant.

However, what constitutes residency can vary down to the local level. It may be up to a local court to decide. Some of the keys in making such a decision is whether the person receives mail at the address or has all their belongings there.

I have a niece and cousin who are staying here temporarily and don't pay anything and are not on the lease and have been here for 50 days and violated our rules and causing health problems with me by stressing me out and I am high risk pregnancy( 3 miscarriages prior) Do I have the right to evict them?

First, please don't start multiple threads over the same issue. If you want to add follow-up info, please post an answer to your thread. I've merged the threads for you.

You have the right to evict ANYONE who lives in your home as long as they are adults and not part owners or on the lease.

You start by giving them a written notice to vacate within 30 days. If they refuse you file for an eviction order.

They do not receive mail here and have been putting my health at risk. I have been threaten and have witnesses that heard it on speaker phone. My sis in law came all the way from southern GA because of it and I have distymia wich is a disorder where I have panic attacks and black out. I don't want to lose my baby and don't want to hurt anyone so what can I do in the mean time. It don't make any sense that someone who was suppose to only be staying 2 weeks but ended up staying 50 days can stay without any agreement or any right in the house can't be throwned out. Exspeacially due to my health.

... I have been threaten and have witnesses that heard it on speaker phone. ...

If they have threatened you with violence go to court immediatedly and get a restraining order requiring them to leave. If the order is issued, the police will enforce such an order.

It don't make any sence that someone who was suppose to only be staying 2 weeks but ended up staying 50 days can stay without any agreement or any right in the house

Yeah it does make sense. You know the phrase; "No good deed goes unpunished". You were nice and you let yourself be taken advantage of. By doing so you gave them rights they don't deserve.

But of there are threats of violence, or you can get a doctor to certify they are creating a stressful situation that threatens your life and the baby's, you may be able to get a restraining order to force them to leave.

Yes it makes sense as it is suppose to be there to protect the person who is staying there from being thrown out without proper notice.

But yes they will have to be evicted. And of they are a danger you get a order of protection ( name varies by location)

... But yes they will have to be evicted. And of they are a danger you get a order of protection ( name varies by location)

Some helpful details are here (http://www.womenslaw.org/laws_state_type.php?id=584&state_code=SC&open_id=11689).