We helped a senior citizen today that had someone move in and refuse to leave. The loving family came in to rescue her. We supported them in finding the digital footprint left by the not-so-nice guest. We recommended the following camera detector to find any listening devices and/or cameras in the house.
Tip: If you log into the router you can see if there are any camera devices on your network. ATT and Comcast both provide apps that allow you wo see what devices are on your network.