Installing a bathroom vent through a wall isn’t a one-way-fits-all procedure. You first find the right spot, so the fan effectively expels air from the bathroom and out through an exterior wall. Then cut a right-sized hole for the fan, so there are no gaps that let insects or drafts to enter. After cutting a hole, install the fan and connect the wiring. While you can do this yourself, it’s better to hire an installation expert to get it right.