I live with one other person but I'll exclude their stuff:

* work laptop * desktop * phone * alexa * tv * nintendo switch * roomba * raspberry pi I use for retro games * an ancient android tablet I use to play spotify * a more modern android tablet I use for web browsing in bed * a e-ink reader * 3 wemo plugs

That's 14

* support wifi that I don't use: tv, instant pot, washing machine, garage door opener, a gopro-type camera, thermostat * I don't have wifi security cameras but lots of people in my area do

I'm probably forgetting things, especially things that support wifi if I wanted them to