Ok this sounds bad but its not for me, my cousin is in some mess with her in laws and asking me this. I honestly dont know what to tell her. Is this even a thing people do?
Haha, unless it's for a movie shoot, don't try it! Fake tests always backfire and then explaining it to the family will be a whole different level of drama.
I understand you might be in a tough situation or just looking for a joke, but honestly, faking it brings so much stress. Please think about it carefully.