This box was exactly what I needed. I already had the screw fittings, https://www.amazon.com/gp/product/B01GJ03AUQ, so I was able to drill a hole and plug the power cord into the box. If you don't need electricity, you're done.
Inkbirdplus Dustproof Waterproof Electrical Enclosure
9 Review
Zulkit Waterproof Plastic Project Box ABS IP65 Electrical Junction Box Enclosure Black 6.22 X 3.54 X 2.36 Inch (158 X 90 X 60Mm)
12 Review
Zulkit 5Pcs Black ABS Plastic Project Boxes - Ideal For Electrical And Power Junctions (80 X 50 X 21 Mm)
10 Review
Protect Your Electronics With Zulkit'S Blue Metal Enclosure: DIY Project Case With Preventive Features (9.1" X 7.3" X 3.9")
13 Review
π‘ Electronic FL Ballast ICN-4P32-N (Formerly ICN-4P32-SC) for 3-4 F32T8 F40T8 F17T8 Lamps, 120V/277V Compatibility
5 Review
Fulham WorkHorse WH2-120-C Adaptable Ballast - 2 Pack
3 Review
π‘ Hydrofarm Quantum QT400 Dimmable Ballast for 400W Grow Lights
5 Review
Wireless Electronic Ballast Interface Certified
8 Review