You attach the fan to the studs in your RV's ceiling, these are the same studs that your current ceiling light should be attached to. Take a look at these Sample RV Ceiling Fan Installation Instructions to get an idea of how these ceiling fans are installed.
If your ceiling light has a wall switch, then you would buy an RV Ceiling Fan that includes a wall switch. If your current ceiling light has the on-off switch directly on the light with no wall switch, then you would buy an Ceiling Fan that is operated by remote control.
If you are going to install a Ceiling Fan in an area where there is no ceiling light, then you will have to find some studs in the ceiling to attach the fan to as well as a 12-volt power source that is close to the installation point you are planning to use. You will also have to determine what 12-volt items are being used by that circuit to ensure that you won't exceed the circuit's amp rating and start blowing fuses when you turn on the ceiling fan.
Depending on the construction of your RV, you may be able to run the wires through the ceiling or conceal the wires going to the ceiling fan by using some Wire Channels.
Take a look at the video below to learn how to install an RV Ceiling Fan
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