https://www.amazon.com/gp/product/B07FZQZ8GF/

It's as if Ikea looked around and asked "how can we make the perfect Lego display case?" because the lighting I linked above is the exact width of the inside of a Barkhyttan box. I haven't yet made an attachment to set the light at a 45 degree angle or I'd include a photo (look for a thread in /lego in the coming days for that if you're interested), but I just received the lights and I had to share. I mean, they're the exact right size for the space.