Did you manage to get rid of it?
Try and pop it outside if you can but do watch if there's a nest.
I left my bedroom window open one hot summer evening and came back to find about 40 of the things going mad round my lightbulb.
I had get one of the lads to go in with a can of raid as there were so many of them and couldn't go back in the room for a day and then there were little bodies all over the place, in clothes, baskets, bags, everywhere.
Turns out they'd made a nest in a bush outside my window (bedroom was on the ground floor)!