The US publication reports that the device will be Google-branded and connect to new Google-made speakers.
It will allow users to download music and then stream their tracks wirelessly to any room.
The WSJ's report follows a piece from tech site The Verve, which claimed that Google employees are testing the device in their homes in the US.
It is currently unclear if the system is related to Android@Home. Revealed last year, the innovation will see household appliances such as washing machines connect to smartphones powered by Google's Android OS.
Google launched its Google Music service in November last year in the US, including a music store that mirrors the music purchasing centre offered to Android customers.