Lighting, Light Fixtures, Ceiling and Exhaust Fans - light box recessed too much

I think I know what I need, but I need to know if it is made, where to get it, and what they are called.

We had to drop the ceiling about 4 inches in one bedroom. The overhead electrical fixture box stayed where it was. I can't install the light now because the screws are long enough to reach.

I need some sort of bracket or extension that I can screw into the existing box that drops down to the new ceiling level and then mount the fixture to that.

Do they make such a thing?

Could you first tell us if the current box is metal or plastic?

Could you first tell us if the current box is metal or plastic?

I believe it is plastic, but didn't notice one way or the other. I can check later today.

Is there an accessible attic above? How was the ceiling lowered. Assuming a minimal weight light fixture an extension box which looks like regular box but no bottom might be the way to go. You might have to use two of them though. Better in my opinion if an accessible attic above is to turn the existing box to face into the attic and splice in an old work box in the new ceiling.

The existing box is metal.