New light bulbs light up even when switched off
The box says NON-DIMMABLE.
You have a dimmer.


LEDs are different from incandescents.

With incandescent bulbs, you can leak a little current through a light and it doesn't matter. You can vary the current and it works fine.

With LED bulbs, a little current goes a long way. So a very tiny bit of current leaked through by a dimmer "nearly off" or for indicator lights/electronics to work when "off" is enough to cause a glow or blinking lights. A larger current in "dim" mode can cause blinking, buzzing or other problems.


  Why is there a buzzing sound when the bulbs work?


Many dimmers work by, essentially, turning the power on/off very quickly. With an incandescent bulb that works great - "all the power 1/2 the time" is basically the same as "1/2 the power all the time" - i.e., 1/2 as much light. With an LED bulb, special circuitry is needed to figure out that "all the power 1/2 the time" means "1/2 the light" and not "turn the light on/off every time the power goes on/off. Depending on the circuitry, a non-dimmable LED bulb can react by:


Turning on/off a lot == blinking
Not working at all
Buzzing as various components that were not designed to turn on/off very quickly end up turning some of that energy into vibrations.


Return the bulbs and get ones that are marked DIMMABLE.