So did you accidently over drill your hole or the masonry crumbled making the hole too big for your wall plug / anchor?

To fix this you will need to grab yourself a piece of old electrical cable (flexible) and it needs to be multi strand copper cable, solid core copper cable doesn’t work for this trick.

You need to pack out the hole using the flexible copper cable with its sheathing use as many pieces as you need to pack out the hole, if you’ve got a bigger gap use thicker calibre cable.

Hit the wall plug home, then clip off the excess cable with some wire snips.

 

Some of the gear I use.

 

To have even more grip you can thread some more copper sleeved cable through your fixture in my case a wooden batten and down through to the centre of the wall / anchor plug.

As before trim off the excess again and you’re done, the wooden batten is super tight and won’t budge.

My last recommendation is that you use harpoon style wall plugs as they give a better grip when the hole is slightly oversized, I’ve also tried to use the Fischer style wall plugs but found they weren’t as good.