My dinette light fixture fell down

When repairing stripped holes in solid wood the strongest and most permanent repair is to enlarge the hole using a drill bit sized to match a wooden dowel larger than the existing hole. Cut a piece of the dowel to fit in the hole or insert the dowel into the hole as deep as possible, then cut off the dowel. Use wood glue on the dowel prior to inserting it into the hole. Then redrill the hole the proper size for the screw after the glue sets.

I have accumulated several sizes of wooden dowels for repairing holes in wood and for other uses.