LEGO Power Functions Pick-A-Part: Led,light,switch,short,long,cable,wire, technic | eBay
High-tech Power Functions Servo Motor Polarity Switch Light Set Ir Speed Remote Control Receiver Battery Box Parts - Technic/electronic Blocks - AliExpress
LEGO MOC Switch Points RC V4 by Technic TRAIN Man | Rebrickable - Build with LEGO
Lego technic electric function switch - max. 24 motors to control - LEGO Technic, Mindstorms, Model Team and Scale Modeling - Eurobricks Forums