I am working on it now.
I will give you a full parts list and a graphic step-by-step. Give me a little time as I will have to check my work. The home made hand sanitizer is kicking in at the moment
I will ask you questions as to flash rate, how many flashes per second that you would like. Have a think about this. I am going for red LED lights with this design.
Getting an LED to light is as easy as stated in a previous post by Datguy. Getting the LED to flash takes a little more circuitry such as a 555 timer chip. Getting the electronics to switch on and off with water contact requires more electronics again, and this is what I am going for with this circuit.
Electronic components come in two sizes; SMD and standard. SMD are miniature surface mount components and are rather specialized. I have never used them, so I have gone for easily available standard components.
If you want smaller, the SMD components have the same pins but will be a lot fiddlier to construct. My design is complex enough, but will be a good apprenticeship.
Dave