My grandmother, who raised me, passed away in 2012. I have been living in the house since I moved in to take care of her during her final 2 years of life. After her death, I asked my aunt, who still lives here too, who now owns the house and she said my grandmother left the house to her. I asked to see the will but wasn't allowed to and I know my grandmother's children never filed with probate.
Recently, I asked my aunt to get a copy of the deed to the house, since it was supposedly left to her, and have her write a letter stating that I live there so that I could enroll my child in school. My aunt said that she doesn't have the deed to the house. Am I legally able to request a copy of the deed and what do I do if no one is listed on it except for my deceased grandmother?

I don't know if this helps but we live in SC and the house and all of the bills are still in my grandmother's name.

If the estate has not been through probate then your aunt doesn’t own the house. The deed would still be in your grandmother’s name. This brings up other issues like are property taxes being paid or ignored.

Are you getting any bills in your name for that house, like a utility bill, phone bill, cable TV bill? Most school districts accept those bills as proof of address.

Property deeds are registered at the County courthouse. They are public record as to who owns what property and what it is worth. Many if not most localities will even let you look this up online.

Do you have ID that reflect your current address? Mail that comes to you? These are forms of ID as well as any bank accounts in your name for the school enrollment. Find out what the school requires.

This site (http://www.wikihow.com/Find-Property-Owners) may help for finding out the name on the deed, but if the will hasn't been probated it may not help much.

In addition to what the others wrote, OP should be aware that wills (if indeed there is one) are not self-enforcing. Simply because someone wrote a will and then dies, does not mean that the devisee (the person named to inherit something in a will) doesn't own the inheritance. A probate application (often called a petition) has to be filed with the court. A personal representative ("executor") is appointed, and a deed conveying the property to the heir or heirs is executed and recorded.

It is an extremely common misconception that, simply because a will provides that so-and-so is to inherit such-and-such, that person owns it automatically. Not true.

Because probate is often expensive (attorneys usually must be hired), it is also common that, when a property owner dies, his family simply keeps living in his home, often for decades and generations. But eventually real property has to be sold or mortgaged, and these matters have to be addressed then.

You should make haste and go to the county office that records deeds. Do not tell your aunt that you are doing this. Check to see who currently has title to the property. If it is your aunt, then ask to see the deed that conveyed ownership to her. That should give you an idea of when probate was filed and you can then check with the local probate court. This is all a matter of public record so there is no reason not to be able to find it.

If no probate was ever filed, then the property and the bills are still in grandma's name. You can then request, through the court, that probate be filed and a will produced. If probate was filed, the will is part of the court record.

You have a right to know and there's no reason anyone should feel like they can't just walk into the deed office and ask. People do it all the time for all sorts of reasons.
Also go to the tax collector or assessor's office and ask who has been paying the property taxes.

Also there could be something else that is going on and the reason that no one has stepped up to the plate and filed a petition. How were the grandmother's finances handled? i.e. SS, bills and taxes paid?

While you are working this will info out you should know that the school district must enroll your child if you claim to be homeless.

... You can then request, through the court, that probate be filed and a will produced. ...

This sentence might be misleading. OP can't simply ask the court to "file probate". That is something that OP (or someone) will have to do. Judges and court clerks rarely are proactive. Litigants, such OP act; courts react.

I suspect that Scott may have meant that OP file some sort of action with the court to require the aunt to file a petition to probate a will. Perhaps where you are, Scott (NY as I recall), but, in my experience, what OP would have to do is file an intestate petition, claiming that (as far as OP knows) there is no will, asking OP be appointed PR, and asking that OP be given authority to transfer the property to the (intestate) heirs. There are other things a PR has to do, but that's the main idea.

Filing thusly will force the aunt to either produce the will or shut up about it.

Yes, I was speaking broadly. It would not be as simple as filing a form to start probate. It would depend on local processes as to what procedure needs to be followed. I felt the OP first needs to find out a) how the property is titled and b) whether a probate was filed. From there they can decide what the next step would be.