Water was coming in between the porch light and hull probably entering through mounting bolt holes or hole for electrical wire on our older style light. When sealing the older style porch lights like we have, 3M 4000 Marine sealant or Marine silicone sealant can be used. This sealant is not used on black gaskets that I believe you have.
Your porch lights have a black gasket between the light and hull. It's possible water could enter the hull if your gasket is not sealing properly and Captain Tolley's might stop it, after reading information about this product. When you visit Oliver they can replace the light's black gasket over the area where the leak is located. We find leaks with a water hose pouring over the area that might be leaking, like you. Oliver can test for leaks, but if you know where the water is coming in, will be helpful information for Oliver. Care needs to be taken when tightening screws on fixtures with or without gaskets on the outer hull to prevent damage to the gel-coat around the fixture.
When camping, if I'm not prepared to permanently fix a leak, also keep a roll of white electrical tape. Used this tape on the exterior where the water is coming in to temporary stop the leak.
Believe SeaDawg recommended another kind of tape in another thread they keep on hand for temporary repairs, too.
We purchased Ollie used and found a few leaks. Once the leaks were corrected, have hardly had any issues with Ollie.
Main thing for us now is keeping the weep slots clear!!!!
Here's the style porch lights we have: