Switches are ideal for controlling wall outlets and devices that cannot be dimmed (e.g., outdoor lights, radios) and standard wall outlets. Wall outlets should never be controlled by a dimmer due to the risk that someone might plug in an inappropriate device (anything with an electric motor such as a vacuum cleaner or fan) which can cause damage or potentially create safety hazards. In circuits where a light is controlled by more than one switch, one Vivido Master Switch and the appropriate number of Accessory Switches (maximum five) must be installed. No traveler wire necessary.