Accessory boxes are predominantly used for which of the following devices?

Accessory boxes are primarily designed to house devices like light switches. These boxes provide a safe and secure installation point for mounting switches, ensuring that wiring connections are protected and that the switch can be easily accessed for operation. The design and purpose of accessory boxes align well with the requirements for light switches, which need to be installed centrally and conveniently for user interaction.

The use of accessory boxes for light switches also adheres to safety codes, as these boxes help contain any electrical connections and prevent exposure to live wires. Their construction often includes features that facilitate the routing of electrical conductors while ensuring that the box itself does not interfere with the switch's operation.

In contrast, power distribution units, heavy machinery connections, and photovoltaic systems typically require different types of enclosures that are designed to accommodate larger components or heavier loads, which are not the primary function of accessory boxes. Each of those alternatives has specific requirements that differ from those of light switch installations, highlighting the specialized role that accessory boxes play in the broader context of electrical installations.