I use these in my MOCS because you can light multiple rooms with 1 string and it's bright enough.
LEGO Polybag - Batman with Octo-Arms foil pack 212010
This was a fun build!
Download Only - Sanctum Sanctorum LED Install 76218 (Instructions only)
Used this for my 6 year-old son’s research project about the yellow seahorse, and it was perfect! He loved it!