I suspect that they will ignore you in a few days, once they see you mean them no harm. I live in Michigan. Hope you will be able to help me. Bird houses should face away from the prevailing winds to prevent rain from blowing in. You might want your wren house to point east, since most bad weather in your area comes from the west.
Wrens seem to prefer houses hanging from a tree limb.
They will be safer from predators than if you mount it in a fixed position. Courtship and nest building begins around April 10th and may continue into early July. Wrens often have two broods per season. House Wrens are more likely to nest in your birdhouse than Carolina Wrens since you are at the northern edge of the Carolina Wren's range. Place the house 6 to 10 feet above ground.