Now that you have successfully made the correct sized cover for your fan install it in the appropriate place.
How to cover an roof fan hole.
Measure the size square then fit it into the opening hold it up and you re going to screw it into the paint stir you only need two screws depend upon the size of the hole make sure you set your screws so there able to be covered with the mud when you mud it.
Roof vent cover from start to finish.
The metal i m using is called crinkle black i purchased all my materials at h.
Use your screws and screw gun to put the cover over your fan.
Typically this is an easy fix mainly because your electric hookups are already in place.
However if you want to forego that cost installing an attic fan can provide the necessary airflow into the attic.