I installed the timer on my bathroom fan. Anytime it shuts off the fan, the lights in the bathroom blink once. lights are on a separate switch, Why???

Hello - this could be due to a couple of different issues. If you are sharing power with the timer and the lights, and the incoming power is going to the timer or light first then jumping to the next device, this could be causing your issue. Another cause could be that the ground is not good on the devices. If you have any other questions or need assistance troubleshooting, please contact our Technical Support Team at Techsupport@eaton.com.