I need some help with this because my husband is busy and hasn't got round
to it. he moved the storage radiator ( on my request) and behind it he has
left two holes which were cut into the plasterboard walling and hidden until
the heater came off the wall. I think they were from some previous wiring
attempt there. I cant say for sure. . One is four inches square and the
other about six inches. How can I fill them up? This needs to be an easy
botch because I am no good at DIY I am fed up of the gaping holes. My
husband "filled" them temporarily with kitchen towel to stop draughts.
behind them is the cavity wall ( I think) - well its a hole there anyway.

Thanks in advance.