Ciao J , sorry for the bad English.
I have another question about Toad, When does he reverts back to his original form?

According to the rules: “When the character reverts back to his original form, remove

the Toad Card and exchange the Toad figure for his character figure at the end of his third turn ."

I think these are the correct procedures:

Situation 1
Wizard’s turn à Wizard casts Random to Ghoul. Ghoul is turned into a Toad.
Ghoul/Toad moves 1 space à FIRST “END OF TURN”
Wizard’s turn.
Ghoul/Toad moves 1 space à SECOND “END OF TURN”
Wizard’s turn.
Ghoul/Toad moves 1 space à THIRD “END OF TURN” à He reverts back to his original form
Wizard’s turn.

Situation 2
Ghoul’s turn à Ghoul moves in the City --> D1 --> He’s turned into a Toad à FIRST “END OF TURN”
Wizard’s turn
Ghoul/Toad moves 1 space à SECOND “END OF TURN”
Wizard’s turn
Ghoul/Toad moves 1 space à THIRD “END OF TURN” à He reverts back to his original form.
Wizard’s turn

I return normal when i collect 3 "END OF TURN" from the moment I am a toad. Is It correct?

What do you think about the first line of situation 2?

There is a correlated question: Toad misses turns. Here the topic

https://community.fantasyflightgames.com/topic/182739-toad-misses-turns/

Yep correct if you have half a turn or even just get toaded somehow after your start of turn then that counts as a turn. I think if you had a start of turn then you have a end of turn given you can really not have one without the other. But... if you miss a whole turn you so not have a start of turn or a end of turn and thus skip the whole turn as counting as a turn for coming back from being a toad. Now some players see it the other way and that's fine. The best way to go is discuss it with your gaming group before a game or come up with a defined house rule. Even though in my mind it pretty "black and white".