A few years back I took a trip to Uman for the Jewish Holiday of Rosh HaShannah. Uman is in the Ukraine and nowadays with a war going on, I don't know if there will be an opportunity to go this year, but I guess we'll wait and see. Peace can come at any moment.
The reason people go to Uman is to pray at the grave of Rabbi Nachman. Rabbi Nachman or Reb Nachman as he is called was a very righteous man and he made a promise to anyone who will come and pray by his grave on Rosh HaShannah that he will do his best to intercede on that person's behalf to have his prayers answered. Reb Nachman also made a promise to anyone who comes to his grave that he will personally pull him from the depths of hell (if he unfortunately has to go there) by his side curls (this is the hair you see on a religious Jew that hangs down from the side of the head).
Just to be clear, in truth, any person at any time can turn directly to God and ask for help. But there is such an idea that the righteous after death do have a special power.

Lyrics

The Promise of a Holy Man

Lived in the room next to heaven a sacred life until he died
When his spirit left his body then he really came alive
Said he’s gonna do what he can the promise of a holy man

He’ll pull you from the depths of despair by the fringes of your hair
Come and pray give charity he’ll do his best to intercede
Guaranteed he’s gonna do what he can
The promise of a holy man

When the righteous leave this world they defend us up above
They can break a bad decree turning anger into love turning anger into love

He’ll pull you from the depths of despair by the fringes of your hair
Come and pray give charity he’ll do his best to intercede
Guaranteed he’s gonna do what he can
The promise of a holy man

Lived in the room next to heaven a sacred life until he died
When his spirit left his body then he really came alive
Then he really came alive, came alive

He’ll pull you from the depths of despair by the fringes of your hair
Come and pray give charity he’ll do his best to intercede
Guaranteed he’s gonna do what he can
The promise of a holy man