The Magic Kingdom cleaned each night. Each land is divided into 2 sections except for Main Street, which is only one. This takes most of the night, but the streets are largely dry by morning. Hosemen are part of the custodial crew, which is also are responsible for mopping, sweeping, and buffing floors. They also clean the restrooms and hose and mop the kitchens.
Electricians change light bulbs.
Nursery crews trim trees and re-plant plants. And maintenance crews fix anything that's broken. The park is full of people 24 hours a day. The sanitation crew works 24 hours per day picking up the garbage and dumping it into the AVAC systems throughout the park. Garbage is literally sucked to a central location for processing.