Can I turn off the lights flashing in the game?

Go to your radar and click on the incoming attack. There is an eye icon that will mute an incoming march. Hope this helps!

Do you mean the red flashing that occurs when you are being attacked. This is a warning and can be very useful. You can't turn this flashing warning off. During the Zombie siege event this can go on for some time but it will stop once the siege is over. There is occasionally a glitch where the flashing continues even after the attack ends. If this happens then you need to close and reopen the app and it should be gone.

If you mean a different sort of flashing please replay with more details.