You need to run three circuits in an existing wall — no access from behind, no option to frame in a new stud bay — and the old work box options all come up short on cubic inches. Box fill violations are an inspection rejection, and a rejected rough-in means tearing out what you just closed up. 3-gang PVC old work remodel box, 55 cubic inches. The capacity handles three devices without exceeding code fill limits for typical 14-gauge and 12-gauge branch circuits. PVC construction means no conductive material near the bundled wires — critical for inspector sign-off in remodel work where the existing wiring configuration is unknown. Standard in the service trucks of electricians running multi-circuit rough-ins and remodel work across northeast Nebraska and northwest Iowa — the 3-gang box that Stocked at Crofton Lumber and Akron Lumber.