How have the courts treated evidence of misconduct in a jury trial?

At this point in the proceedings, defendant's sole evidence of misconduct consisted of a lone individual's statement containing several levels of hearsay. The statement listed none of the names of the persons involved, and the details of the alleged misconduct were vague. The facts here resemble those in People v. Jefflo (1998) 63 Cal.App.4th 1314 [statement by defendant's girlfriend that a juror told her the jury had hung was not a showing of good cause sufficient to warrant a hearing]. Nonetheless, the trial court held a hearing and released the alternate juror's information. The court did not abuse its discretion by refusing to release all of the jurors' information at that time.