Typical house with a basement, there are about 4-5 renters.
There is a Cat6 line going from my main router to downstairs, which is then connected to a signal booster to give them all wifi.
I’d like to keep the renters completely seperated from my main house home network.
How do I seperate the signal booster/renters from seeing any devices on my main house router?
Should I connect a switch or router in between my main router and the signal booster?
Your best option is use VLANS your consumer router may not do it. So may require setting up an open router and run like OpnSense etc