What must be installed with devices using the mounting strap of a switch if it has a non-standard nonmetallic faceplate?

The correct answer highlights that when a device using a mounting strap has a non-standard nonmetallic faceplate, there are no specific requirements for grounding. This is based on the understanding that nonmetallic faceplates do not conduct electricity and therefore do not present a grounding hazard.

Grounding requirements are primarily focused on preventing electrical shock hazards in areas where metal parts could become energized. Nonmetallic materials are insulating and, when properly installed, inherently reduce the risk of electrical shock. Consequently, if a nonmetallic faceplate does not provide a conductive path to ground, the device it covers does not require an additional grounding mechanism beyond what is already present in the circuit.

This awareness allows electricians and installers to approach grounding and bonding with an understanding of the materials involved and their properties. Nonmetallic faceplates serve their purpose effectively without necessitating additional grounding measures, making the choice of no requirements for grounding an accurate conclusion within the context provided.