I SAW THIS MOVIE WHEN I WAS ABOUT 16. THE MOVIE STARTS WHEN A BOY
MOVES IN WITH HIS GRANDFATHER. THE BOY START TO SEE THIS LADY IN RED
WHICH TURNS OUT TO BE HIS GRANDFATHERS SISTER WHO GOT KILLED TRYING TO
SAVE A DEER ACROSS THE STREET. A GIRL NEXT DOOR STARTS TO SEE THE LADY
TOO. THE BOYS GRANDFATHER AND THE GIRLS GRANDFATHER DON'T LIKE EACH
OTHER. HE THINK THAT THE GIRLS GRANDFATHER KILL HIS SISTER. FINALY THE
MAN SEE HIS SISTER. AND TELLS HIM WHAT REALLY HAPPENED TO HER. THE
LAST THING I REMEMBER WAS THE BOY AND GIRL FIXED UP A HOUSE TO
FRIGHTING THE BULLY KIDS AT SCHOOL..

Hi coal32,

I believe the movie you are looking for is called "Believe".

"After being continually kicked out of boarding schools, Ben is sent to live 
with his stern Grandfather in a small town. While there, no one is interested 
in him with the exception of a girl named Kathrine. The two become
fast friends despite the unexplained protests from Ben's grandfather
and
Katherine's uncle. Almost as soon as he arrives, Ben begins to see the
ghost of a woman around his grandfather's house. He and Katherine want
to help the ghost who holds a connection to both of their families. As
they research the past, Ben and Katherine find out that sometimes all
you need to do to
help someone is to believe."

IMDB
http://www.imdb.com/title/tt0207333/plotsummary
http://www.imdb.com/title/tt0207333/


"Ben Stiles is expelled from boarding school for a prank in which he rigs a 
ballroom to make it appear like a ghost. Ben's father, a busy diplomat, sends 
Ben to stay with his estranged father who lives in an imposing country
mansion. There Ben sees the ghost of a woman. But when he tries to
find out who she is encounters a wall of denial from his grandfather.
He befriends and becomes involved with a neighbouring girl, Katherine
Winslowe. The two team up to create a fake haunting to deal with two
bullies and to try and solve the mystery of the ghost. But their
investigation is hampered by both her uncle and Ben?s grandfather who
forbid them to see each other again. Defying either, they try to dig
into the scerets of the past that both elders want to keep buried."

The Science Fiction, Horror and Fantasy Film Review 
http://www.moria.co.nz/fantasy/believe.htm 


This movie is available on DVD at Amazon:
http://www.amazon.com/gp/product/customer-reviews/6305785252/


Search criteria:
movie ghost boy "his grandfather"
movie Believe "his grandfather"
movie Believe "Ricky Mabe" 

I hope the information provided is helpful. If you have any questions
regarding my answer, or believe this is not the movie you are looking for, 
please don?t hesitate to ask for further assistance before rating.

Best regards,
Rainbow

very fast service. I have been looking for yers. will use this site again

Hi coal32,
Glad I could help. Thank you for the rating and tip.
Best wishes,
Rainbow