Remote ceiling fans come from the factory with default dip switch settings. The remote's receiver module has frequency dip switch settings that must be the same for the transmitter and the receiver. Each unit has four sets of on/off switches that determine what setting the frequency is on. The default settings for a new remote ceiling fan are 1-on, 2-on, 3-on, and 4-on. If there are other ceiling fans in the house with remote controls, then those ceiling fans might have the same frequency settings. Therefore, each time one ceiling fan is turned on so is the other. This also applies to apartment buildings. If this problem is occurring, most likely the frequency settings are the same as the other ceiling fans in the apartment building. You can change the frequency dip switch settings on the ceiling fan remote and ceiling fan receiver that is turning on by itself.