Furni and wired needed:
- 1x WIRED Trigger: Furni State is Changed
- 1x WIRED Effect: Toggle Furni State
- 1x Switch
- 1x Gate 

First Step:
Place your WIRED Trigger: Furni State is Changed and attach it to the switch that you are going to use. 


Second Step:
Place your WIRED Effect: Toggle Furni State and attach it to a door you already placed.


Third Step:
Stack the WIRED Effect: Toggle Furni State on top of the WIRED Trigger: Furni State is Changed and now you can open a door using the switch.

After following all the steps correctly, you should now can open a door using a switch. If you have trouble in making these, please find me on Habbo and I'll gladly help you if I can. Hope this guide helps you!