I was in the process if hanging curtains and when I was putting the drywall mounts into the wall the drywall was extremely hard and just crumbled. Once the drywall mount hit a certain depth it just stopped. I know there is not a stud in the wall at this spot, i checked with a stud finder.
I don't think the wall is plaster. I even took a light switch off and looked behind it to confirm. Maybe I'm wrong though.
Am I dealing with plaster... can the drywall harden or become brittle over time?
If it is plaster is there a good way to mount these curtains in the plaster.