@Sooty you are correct that's not a moth, in Australia we have even bigger ones for example: The Rain Moth, with a wing span of 16cm and a body length of 12cm, here is a photo. The Wood moth Females can weigh up to 30 grams and have a wingspan of up to 25cm. Males are half that size. That's just two of the moths here and there are lots more.
.. I think I would be more concerned about the lamp getting knocked over if they came flapping through the ether..