Something connected to my wifi

It is a Generic Device. Generic devices are those devices for which Fing was not able to identify the vendor and what kind of device it is. If there is any device in your house which is using any kind of internet(Wifi) then Fing App can show you all devices connected on your network. You can use this external link to know about the vendor of the device: https://aruljohn.com/mac/F45EAB 

 The Fing App discovery will identify devices on a best effort basis, based on the information made available by the device, e.g. the MAC address. There are numerous reasons why the device might not be recognized correctly e.g. 

 - The DHCP server is not refreshing when speaking to your Fingbox. 

- Limited information being offered by specific devices.