Unknown device connected To WiFi at 1am

Last night around 1am, I received an alert that a new device connected to our WiFi for the first time. It was a generic brand Android device, I tried looking up the MAC address and it was associated with “Ralink Technology Corp.” The hostname started with Amazon and then a bunch of numbers. Any idea what this could be? We don’t have any new devices. We also don’t have any Android devices. I changed our WiFi password but I don’t understand how someone could’ve gotten it. Any help or direction would be appreciated.