My boyfriend has his ex girlfriend living with him "temporarily" and I am afraid that she will try to get him back. I need a non-violent spell that will move her out of that house of good and keep them apart.
Nord is right that it is important to take the required actions in the mundane world. You can use a banishing spell such as toss a symbol of the girlfriend or something containing her energy into a receding tide to "carry her away." I strongly advise you to learn the basics of spell casting before any of this, and feel free to modify a spell or create one of your own.