electrical box not stble

i moved into an old apartment. the electrical outlets were all upside down and fall out of the wall. i unhooked the power and looked at it and the boxes are loose in the wall due to nothing behind the metal boxes. they just sort of rest in the space that was made for them rather than allowing for a screw (it wont connect to anything). hwo can i fix this issue? do i just have to cut a new hole?

What is the wall made of?

Not sure about the US, but here in the UK there are special boxes made for hollow walls.