I am interested in a "smart" light switch. How do I make one?

Hello.
I would like to use something like this in a house I am building to switch on lighting:
http://www.elkosmito.pl/index.php?id=produkt.php&produkt=40
or
http://www.elkosmito.pl/index.php?id=produkt.php&produkt=64
Is anyone able to "guess" what components will be needed for this to assemble something like this myself?
Mainly I don't know what the component at the bottom of the board in the first address and the component on the left in the second address are.
I think something like this is very practical and many people would be interested in putting something like this together.
If anyone has any suggestions then please feel free to join the discussion.
As for the statements to buy a ready-made one, please refrain, because firstly the lack of $$$, and secondly I like to rummage around in different areas and always go to learn something new .
I searched for schematics but maybe ineptly or just didn't find the right one. They were on a 555 circuit and this visually does not look like one to me

And what exactly do you want to achieve?

So I would mainly care about the former device.
Turning on lights temporarily and permanently with one monostable button (bell, pulse) or in the case of the stairs two such buttons but then just connect the switches in parallel to one board and it will be the same as with one so no need to go into the rest.
There doesn't need to be a potentiometer in this set up for me - just adjusting the element for, say, 3 or 5 minutes without smooth adjustment.
And the relay something doesn't suit me on this unit as it appears to have a 12v coil(?).
This second scheme would be a good option for connecting a light in the hallway, because instead of giving a switch at each door you could give such a proximity element and it would be almost invisible and not disfigure the wall.
But as I wrote above, I am mainly interested in the first scheme, and the second one, because of the fewer places I would plan to use it in, maybe one day.