[morzh]

Here.

Take a solid state relay.
Make the switch input powered through an RC. Or a 555 timer. With 20 seconds delay.

And from here you could be as fancy as you like. I do not exclude a possibility of using some microcontroller and even AI. In the latter case make sure it has a display, where for 20 seconds there will be a middle finger displayed and some pleasant voice will tell you were to go and what to do.

Then after 20 seconds it will say "OK, ok...now".