Help/ideas

[J2k]

Good evening

I removed an old alarm sensor from the corner of the ceiling/wall in the living room and I have now been left with this gap. Any help on how to fill it or any ideas of what could fill it with? (Not another sensor)

Thanks
Jordan

 

[Doghouse Riley]

To be honest I'd have left the sensor there. You could have painted it white if it bothered you.
I presume it's polystyrene coving?
Just pack it out with some newspaper, dampened with some wallpaper paste, leaving about a quarter of an inch. Make sure it goes behind the edges of the coving, but be careful not to damage it. Let it dry, then just skim over the surface with some Polyfilla. Then paint it. You'll still probably notice it, but no one else will.