This episode is a bit more advanced with new things such as custom functions and dealing with arrays/loops. To support you in this i would recommend watching the interactive door tutorial first.
Resources
Wall Light Switch: https://www.dropbox.com/s/gq088ch5zq0n22u/wallswitch.fbx?dl=0
If you get stuck, have issues, or any questions about this video topic, please leave a comment below and I will try my best to answer them for you.
Source