Final answer:
The error in the sentence is that 'OVER NIGHT' should be 'overnight'. The corrected sentence is 'PLEASE DO NOT LEAVE YOUR CLOTHES IN THE LOCKER ROOM OVERNIGHT.'
Step-by-step explanation:
The error in the sentence 'PLEASE DO NOT LEAVE YOUR CLOTHES IN THE LOCKER ROOM OVER NIGHT' is that 'OVER NIGHT' should be one word instead of two. The correct phrase is 'overnight'. Therefore, the corrected sentence should read:
PLEASE DO NOT LEAVE YOUR CLOTHES IN THE LOCKER ROOM OVERNIGHT.