My C150 has been hangared since my purchase 21 years ago. The only times that it would be outside was when we went to our condo in Palm Springs in late August it doesn't rain in August.
Recently I needed to park the plane outside for a few days while I moved stuff (technical term) around in the hangar. It rained steadily those two days. When I brought the plane back into the hangar I noticed that the carpeting was wet, so I removed the carpeting so that it could dry. Searching the internet I found that there are fairings that fill the space between the end of the flaps and the fuselage underneath those fairings are the cables for the flaps and ailerons. If the fairings are not sealed to the wings, then water can get in soak the carpet. I removed those fairing and found that there had been at least two previous attempts to seal the fairing to the wing. I checked AS&A and found this
https://www.aircraftspruce.com/catalog/appages/windowsealant.php which I used to cauk the fairings to the fuselage. We just need some rain now to check if it works.
I am now praying for rain, and I am praying that the plane doesn't leak anymore.
