Have found 1 screw loose on one of the fixtures, but never took out both screws to see what they were installed into. If it is only the one eighth inch thick ceiling board...there is a simple trick to making sure the material doesn't enlarge the holes by itself from travel motion. If you squeeze a little thin ca glue into each hole and let it dry, it soaks into the wood and super hardens the material. And this allows the screws to have a secure bite. John
2012 F350 6.7 L dually, 2013 3800RE with 6 pt leveling, Sumitomo 17.5" load range h tires, Samsung 18 cu ft residential fridge, 8k Morryde I.S. with disc brakes. Full timing since 2012.