Don't put the WiFi there. Use the old spy camera that puts video on 2.4GHz and then the receiver goes to the box that puts it on WiFi.
If you don't understand this answer, it means you need to do more research. Been there!
I am designing a miniature camera as small as possible. I need it to be able to stream the video wirelessly. I need help figuring out how to connect the camera lens to a wifi-transmitter and power supply. Any ideas??