My cat LilEli fell out of my livingroom window when I lived in Michigan. I lived on a MAJOR busy street and didn't even hear the screen give way. LilEli was a feral kitty, being born to Zam (Ramanth's kitty) along with Logan (also Ramanth's kitty).

I put a trap out in the back yard with the hopes of catching him. I tried for 6 days and 5 nights without success. One night I was pulling into my parking spot and there he was just sitting in the back yard. He had been in the craw space inside the entrance to our building's basement. I scooped him up in my arms and took him inside and checked to make sure he was okay (nothing broken).

I would suggest that your aunt and uncle put up posters (someone may have closed him in a garage, tool shed, etc.), and check the perimeter of the house. Shake a can of treats and call his name. If he's hungry enough, he'll come around. Cats do not roam far from their food source.

Good luck.