As an overnight cleaner, you work in an office or facility after hours, performing cleaning and maintenance duties. Your responsibilities include dusting surfaces and fixtures, sweeping, mopping, and vacuuming floors, washing windows, and cleaning bathrooms. You monitor inventory and stock of cleaning supplies, empty trash cans, and complete other cleaning tasks as needed. You may make minor repairs or adjustments, and notify management for larger projects or issues. You may also use heavy equipment like a floor buffer.