My husband and I have some serious issues with the walls in our house. It was built in 1996; we live in CT. This is the 2nd time we’ve tried to hang something on a wall, and it has turned disastrous. We bought the self drilling drywall anchors recommended to us at Home Depot (TOGGLER SnapSkru). We used a philips screwdriver and once it gets to the threaded section of the anchor, it just chews up the Sheetrock. We are now left with a hole that we need to patch and try again but I’m afraid. We made sure there was no stud behind the Sheetrock. This is the second spot in this house that this has happened. Ace Hardware and Home Depot were no help. They recommended the same anchors again. I don’t know what to do and we’re having a screaming match over this. This should be easy, shouldn’t it?!
The Toggler SnapScru product you used is decent, with two cautions: 1, you need to maintain solid pressure while driving it in. Doing this with a screwdriver is somewhere between tough and really hard -- you want to use a drill or an impact. 2. If you hit something solid, you'll just chew up the drywall.
If you did hit something solid, (and you know it's not electrical cable or plumbing), just use a regular screw. Probe with more than a finish nail to be sure that you aren't just getting minor pushback from insulation.
If you have air behind your existing hole, go back to your favorite big box store and get the "Toggler Snaptoggle". It goes into a 1/2" hole and you pull it back on itself for a solid mount. (As solid as drywall, that is. Don't do chinups off this.)
Technique I've used with this type of anchor:
Put a #3 phillips bit into my drill.
Drill at the location I want.
Stop when the screw is just flush with the surface.
Swap bits for a #2 robertson.
Throw way the slot screw that comes with the anchor, and use a robertson of equal or shorter length. If you are in the part of the world where robertson screws are unavailable, use a phillips.
Pressing firmly, slowly drive the screw in.
I see you used something similar to this
Except it looks like you were trying to do it by hand, that's rough... you definitely need a power tool for both the anchor and the screw that would go in the center.
You dont need to have anything behind the drywall for it to attach to, they were designed to make an empty drywall space that's missing a stud sturdy enough to hang or hold something like a picture or shelf
If you hit something behind the wall and it wasnt detected by the stud finder, then your stud finder might not be calibrated correctly or theres thermal insulation between the finder and the drywall, either way the best and safest solution to proceed any further would be to purchase an endoscope to see what's lurking behind the wall.
You might be able to determine what it is just by sticking a long nail in there to see if it moves at all, because the last thing you want to do is run a screw into an electrical wire. If you jam a screw in there by hand does it feel different or does it feel like a solid piece of wood.