Per Idlehands:

My research indicates you still need power to the wireless cameras,
either way you are dealing with pulling wire. Unless you have a
convenient outlet to plug the camera power supply into.

Maybe others have had better luck, but the couple of WiFi cams I tried
were pretty much hopeless. IIRC at 640x480 they were barely functional
and anything higher was totally useless.

OTOH it might say more about the quality of my WiFi than any device...
but I am heavily biased in favor of hard-wired Ethernet whenever
possible.
--
Pete Cresswell