What is the purpose of an offset bar hanger?

An offset bar hanger is designed specifically to provide support for electrical boxes in locations where they need to be mounted between joists or studs. This is particularly useful in residential construction where the spacing between structural elements may not allow for standard mounting methods. The hanger allows the box to be securely attached while also maintaining the necessary alignment and support for electrical connections, ensuring that the installation is safe and compliant with electrical codes.

The other options relate to functions that are not applicable to offset bar hangers. Holding drywall, attaching heavy appliances, and hanging curtains require different types of hardware or methods to achieve secure and appropriate installation, which do not involve offset bar hangers.