The film, which is a children drama, has been produced by Ravi Chopra and has been directed by Vivek Sharma.
The film also stars Shahrukh Khan in a special appearance, besides Aman Siddiqui and Priyanshu Chatterjee.
Bachchan is playing the role of a friendly ghost in "Bhoothnath", which literally translates into 'Lord of the Past' and not the tongue twister "Bhoot-nath", meaning 'Lord of the Ghosts'.
Juhi, who is cast opposite Bachchan and is playing the role of a mother, said: "The story revolves around what all happens when this little boy meets the spirit and then fights between them and their friendship and other things that happens between them. So it's fun because there are lots of shades to it. It has fun element, drama and emotions as well."
The film revolves around the ghost of a grandfather (played by Bachchan) that appears to his grandson.
Juhi was excited about her first song ever in cinema, - a duet with Bachchan.
"It was my first experience being in that little song, dubbing box that they have and trying to do this. Although we do dubbing in films, but this was totally different thing," she said.
'Bhoothnath' also marks the return of Juhi, who was recently seen in a supporting role in the film "Krazzy-4", in a lead role after her marriage.
The film is a story about a seven-year-old naughty yet innocent boy, who unknowingly turns a foe into a friend.
Contrary to the name, 'Bhoothnath' is hardly spooky as it projects a congenial relationship between a kid and the ghost.
To make matters humorous, this jovial ghost is dressed smartly and sings and dances rap numbers with the kid. The film prompts adults to see the world through the eyes of a child.
The B.R. Films production 'Bhoothnath' is all set to hit theatres on May 9.