A ceiling fan is a device suspended from the ceiling of a room, which employs hub-mounted rotating paddles to circulate air.
In the United States, the National Electric Code (document NFPA 70, Article 314) states that ceiling fans must be supported by an electrical junction box listed for that use, such as a metal junction box, not plastic. However, some junction boxes installed for ceiling mounted light fixtures do not meet this requirement. It is a common mistake for homeowners to replace a light fixture with a ceiling fan without upgrading to a proper metal junction box; failure to use a proper junction box may result in a fan that wobbles or worse yet, a fan unexpectedly falling down.
