After browsing the web I have found that master caution buttons ready to use are quite expansive (something like 50EUR or more). I found that price so unbeliavable for a single button that Ideide to try to build one from scratch.
I bought two squared pipes with a very similar size in such a way the biggest one surround the little one leaving a very little space. I will put the leds into the little one while the bigger one moves forward and backward. When in backward position it will press a switch in order to clear the warning.
I kno that what I said is not clear enough. If I have enough time I will draw the project and put here an image.
I still have some concern about this idea but I found it a very interesting challenge.
That´s it for now. Merry Christmas and happy new year to everybody!