Legrand - OnQ 12 Inch Cable Management, In-Wall Media Box, Structured Wiring Enclosure, Home Networking Panel with 2.5 Inch Openings for Wires, Glossy White, EN1200

Since it will be flush, what are you doing with the wires? I mounted a couple of LG G series OLEDs years ago that are completely flush with the wall. I used these without the cover to hide everything. Legrand Structured Wiring Enclosure