This article explains how to use Amazon Echo devices as night lights in different ways.
How to Turn Your Echo Dot Into a Night Light | Amazon Alexa
Neither Echo nor Echo Show devices have built-in night lights, but there are ways to use them that way. Smart speakers like the Echo and Echo Dot have light rings that you can illuminate to act as night lights using the appropriate Alexa skill, while the Echo Show has a display that can be used as a night light if you manually adjust the settings.
The Echo Show doesn’t have a night light feature, and there are no night light skills that work with the Echo Show. While you can use Alexa as a night light with most other Echo devices, there’s no easy way to do that with an Echo Show.
If you want to use an Echo Show as a night light, your best option is to turn off the adaptive brightness feature, turn off the auto-dim feature, and then manually set the screen brightness to the level you want for a night light. The screen will then stay at that brightness all night.
