Switching external device with XIBO for Android

I have a specific project which is digitalsignage related but customer is asking for special feature. I would like to ask if you have any idea how we could do it.
We have standard LCD with Android for digitalsignage, we plan to use XIBO for content management.
But customer have next to LCD a trafic light “green, orange, red”. Classic traffic light as you know it from street. It is intalled next to the screen. Now what they need to achieve is to controll a lights via player, to be able to change the light colors.
Lights are having separate power supply so we need to only achieve the switching and control.
thank you for ideas and suggestions.