When you posted your question I received an email with every post ever made of light house patterns. Last summer when I went through these I found most useful the school project. It is on a very small scale but it gives you the idea of what is needed in cuts and angles. The other thing I did was google "free light house pattern" and I got one or two and when I looked into the cost of the construction or the purchase of the light fixture, it was cheaper to buy one already made. I found those by googling too. The other thing I found useful because I then realized there were so many designs was to google images of lighthouses so I could chose the style i might build. You can make your own and I even got creative with the design of the light. I picked up a perfect size old fashion metal camping lantern and liked the style of that for the light using most of it's parts, especially the roof. But then realized also those emergency lights or heavy duty commercial lights you might find in a parking garage have a cool design. A cylindrical thick lined or pitted light shade and the ones with a metal cage over them have an interesting look.
My sister said instead of me going through all this since I have to rebuild a pond at the house I moved in she would get me one from a neighbour who builds them out of upside down clay taracota pots...
I will get my lighthouse one way or another. Good luck on your search...