There's a beautiful Gothic Lantern on Thingaverse that needs LED lighting. I've inserted various lights and they all look Great. (https://www.thingiverse.com/thing:2395716)

Then Adam Savage blew my mind. There's a 'Fire Bulb' out there that plugs into a 110V outlet, and looks like fire (many manufacturers, here's one: https://www.amazon.com/Simulated-Decorative-Atmosphere-Christmas-Decoration/dp/B0791BWFCL).

Adam found that if dissected, the LEDs inside ran on 3V. A pair of AA batteries. (https://www.youtube.com/watch?v=JMv0PlMKkbs)

I created this mount to put two AA batteries, and suspend the dissected Flame Bulb inside the Gothic Lantern. It's a great combination.