‘Every move he made was uncertain, as if he were not sure his hands and feet could make proper contact with the things he touched.’

In this sentence, yet again Scout portrays Boo as a ghost. Stereotypical ghosts are most often not solid forms. They pass through things and thus cannot come into contact with anything for they go straight through it. She represents Boo to have this ghostly trait by saying he moved as is his hands and feet couldn’t make proper contact with anything, as if he knew he were a ghost and would pass straight through them.