We have a somewhat "smart home" with the Ring alarm, Ring camera, and Ring doorbell, as well as several other "smart" devices (Bosch fridge, wemo plugs, amazon plugs that work with Alexa, Rachio sprinkler control, Nest thermostats, Kasa outdoor plug, TVs, and Roomba).
We had a troubling incident a few weeks ago that resulted in us pulling all of the Alexa items from our house. DH and I were out to brunch, and a repair man showed up at our door to fix our dryer. The thing is, no one called him to fix the dryer. We asked where he was from (real company), who scheduled it, etc. We DID have a problem with our dryer, but we had not told anyone about it. It was only a discussion in the home. DH contacted the repair company to dig into it a bit deeper. While they didn't have our name, they did have our address. The repair was scheduled online with an obviously fake email address and an obviously fake name.
There has been no recording of anyone coming into the home when we're gone. All entrances and exits have a camera, and we have an alarm that is set every time we leave the house. DH works from home, so there are very few times when no one is home. We did have a dishwasher installed right before Christmas, but I can't imagine them putting some sort of spy device in the house.
We have reset the wifi network and removed anything that tried to connect that is an "unknown" device. We get a notification each time something connects, and we either identify and name it or block it. There is nothing that has tried to connect that we don't know about.
The kids were not involved, and their friends didn't know about the dryer.
The only thing we can think of is that someone was listening through the Echo dots. We had one in the kitchen that we used all.the.time. for various things, as well as one in our bedroom and one in each of the kids' rooms. I don't know that we'll ever figure out how this happened, but it has been unnerving, to say the least.