I took old cover from plastic sewer pipe (it was never used ha ha). Then I drilled four holes for M3 screws and one bigger hole for camera module lens. The housing was prepared from one litre PET bottle. I cut the bottle to proper size and inserted raspberry Pi with the camera inside the bottle. Next the LAN cable with passive 5V “PoE” was inserted.
Finally, I heated the bottle with hot air gun at the camera side to shrink a little bit and tightly close the gap between the plastic camera “holder” and the bottle .
Photos below will tell more than thousand words: