@Houndstooth Thanks so much for the suggestions as to what may be happening. What is unique to this situation, when I get the notice that the device has connected to the network, it states the name...

@Alexandre. Thanks for the link. I had read that article but it doesn't address why someone unrelated to my household could connect to my password protected WiFi. It has happened multiple times over...

I am getting notices that an iPhone has connected to the network. Problem is, it's not mine of anyone associated with the household. Deco X60.