How Would You Fill These Holes

[HugeWesty]

I know I've left the door open for complete smut, but how would you fill deep holes like this? These are from old and now disconnected (done by electrician) electrical interfaces.

Thanks

 

[sircerebus666]

Is that cable live ?

 

[HugeWesty]

Is that cable live ?

No definitely not. Confirmed by electrician and I also have a pen detector thing which confirms too.

 

[sircerebus666]

Then I would remove the cable and back box, square off both holes , cut a scrap piece of timber/plasterboard which is the same width as the hole but longer and glue it to the inside of the hole using string to hold it in place until the glue dries.

Once dry use filler to finish off

 

[JohnD]

I would remove the boxes, clear out rubble and dust, wet it, and fill with sand and cement mortar, pressed in very hard and built up from the bottom in layers so that slump does not leave shrinkage gaps. Mortar is strong enough to take screws later, and has a long working time. It will restore the integrity of the wall. Finish it a quarter inch or so below the wall surface and the next day use finish plaster. Thick plaster cracks and is weak. With practice, you can get a superior finish with plaster, it is better than filler.

Press down very hard and scrape off any excess while it is still cheesy. Avoid sanding.