These are tiny warm white LED modules you use just like grain of wheat bulbs but they run cool, last longer and use much less power. At just 7mm x 12mm they can easily be glued into the inside of a house to illuminate through the windows.
10pcs Warm White LED Screw Bulb & Stand E5 E5.5 12V-14V HO/TT/N Scale
10pcs Warm White LED Screw Bulb and Stand Base E5 E5.5 12V-14V HO/TT/N Scale
10pcs Warm White Screw Bulb E5 E5.5 Leds 12V 14V HO/TT/N Scale E505WM
OTOTEC 10pcs 12v LED Light Board Model Railway Building Interior Lighting Warm White LED Compatible with Hornby OO HO Model With Wire
Kato Warm White LED Coach Lighting Set (6) 1:150 Scale, N Scale