Did you inadvertently have an unseen lodger Alison? I agree with Wendy that the moth is Uraba lugens and to the best of all out combined knowledge, the case is a Psychidae.
That is very odd because that is not what Uraba lugens pupates in that is the case of a psychidae see Uraba lugens (Gumleaf Skeletonizer) http://lepidoptera.butterflyhouse.com.au/noli/lugens.html