In the middle of the night when a mosquito is buzzing around my head but I can't see it what is a good way to attract it so that I can smash it and get back to sleep?

Put a light on. They are naturally attracted to light. They will stay in the light and you can swat it there. What I do is turn on a porch light, on my front porch, while leaving all other lights off, then leave the screen door shut and when the mosquito goes to the screen door to try to get to the light, I let it out. It works for houseflies and many other flying insects, too.