On 2008-01-17 23:17:27 +0000, "The Medway Handyman"
said:

Dave Plowman (News) wrote:
I need to fill a hole where a downlighter was in a (skimmed)
plasterboard ceiling where I don't have access to the back. It will
be painted afterwards. What's the best way for an invisible repair -
it's in rather a noticeable place. The skim is the pink stuff.

Get a short piece of wood & partly insert a screw halfway along. Poke into
hole & centralise. Pull down on screw to hold in place while you screw
through plasterboard either side of hole into wood. Remove partly inserted
screw.

Cut a circular piece from some scrap plasterboard as close as possible to
the hole in the ceiling.

Now screw plasterboard bit into wood. Fill around edges.

Good solution.

I like to augment it with some grey Gripfill if it's a lath/plaster
ceiling, or the mimsy-water-based version for plasterboard. Then it
doesn't matter if there is some movement with the screws.