I often stay long-term in a particular Homewood Suites in the US. I don't feel I need my bed making and new towels delivered every day so I leave the DND sign on the door. Every time, without fail, when I get back from the office there is a flashing light telling me there's a message from front desk asking if I want my room made up. I started to unplug the phone when I get in from work and every day (when I don't use the DND sign) I come back to find it plugged in again.