The lighthouse is a permanent fixture of the beach! It has been used and referenced in several past events.

It's still accessible and player characters wouldn't have a difficult time entering it. Trying to take a sample of the fuel for the lamp would be suspicious and considered stealing if caught, but would be possible if they're stealthy enough. However, the fuel which caused strange effects as per the prompt in question was a special batch of contaminated fuel. It's long gone and any fuel stored there now would be normal.

For any more specific inquiries relating to a potential player plot, please comment to the Feedback/Player Request Page!