Yes, you can use it without an existing doorbell!
Wyze Video Doorbell Pro is a wire-free doorbell that has an internal, rechargeable battery. While it can be hardwired to existing doorbell wiring for persistent power, it is not required and can be used and mounted without any wiring.
Important: A Wyze Chime Pro is required to use a Wyze Video Doorbell Pro, as it provides the connection to your Wi-Fi network. Even if you use your mechanical doorbell chime, you must use the included Wyze Chime Pro as well.