What kind of bug is flat and looks like it's covered in sand?

Question

What kind of bug is in my house?

It looks like a piece of debris, like sandpaper. But it moves, it's looks like it's covered in sand.

It's flat.

It's gray in color.

It's about the size of a finger nail.

It's long and skinny.

It's narrower on the ends than in the middle.

I found one on the wall and one in my bed.

I can try and get it out of the trash and take a picture if you need.

Answer 1

Is this what it looks like?

http://bugs.com/plaster_bag.html

Answer 2

It sounds like a bug called "silverfish"

Answer 3

That is a plaster bagworm.

Hard to control.