You aren't specific about the chapter, but I'll try to give you a general answer.
Both Jem and Scout shed tears a few times during the novel. It's a natural response for a child--sometimes out of emotional distress and sometimes to seek attention. Jem's tears always come as the result of a new revelation: He cries after finding out Nathan Radley has lied to him about his reason for cementing the knothole; he cries after Mrs. Dubose hurls insults about Atticus, who always treats her with respect; and he cries about the jury's obviously unjust decision in the Tom Robinson trial. Jem is also maturing and going through the first stages of puberty, so the tears come more uncontrollably than he may wish. Meanwhile, Scout's tears usually come out of anger, in much the same way that her brother's flow.
Doors, especially the closed doors of the Radley home, represent an entrance to a different world, one that is foreign and enduringly mysterious to the children. The courthouse door serves in a similar manner. Jem, Scout and Dill view ghosts in much the same way as other children of the period: They consider them real entities when they are younger, but both Jem and Scout laugh about them later in the novel, the ghosts, Haints and Hot Steams symbolize maturity having
... vanished with our years as mist with sunrise.