Once the mounting bracket is firmly in place ... Step 2: Find and Inspect Your Doorbell Transformer Use a multimeter set to ...

If you're uncomfortable dealing with the transformer, call a licensed electrician that can test and install a new one for you ...

If not, then it may be located near a wired doorbell chime. Before you start the install, turn off the circuit breaker. Rachel Cericola/NYT Wirecutter Check what voltage your transformer puts out ...