LEGO PART 62930 Light Brick 2 x 3 x 1 1/3 with Dark Bluish Gray Base [Yellow LED] | Rebrickable - Build with LEGO
Amazon.com: Lego Parts: Electric, Light Brick 2 x 3 x 1 1/3 Red LED Light (Trans. Red) : Toys & Games
LEGO PART 62930 Light Brick 2 x 3 x 1 1/3 with Dark Bluish Gray Base [Yellow LED] | Rebrickable - Build with LEGO
Amazon.com: SCS Direct Light Up Building Block Bricks Set of 8 (2"x3") with On/Off and Dim Ability - Multicolor Light for Each Brick Compatible with and Tight fit with All Major Brands :
LEGO Light Brick Internals and Color LED Replacement - YouTube