What happen to job applications and other types of applications after time?

After you have applied for a job, volunteer opportunity, or any other type of application, what happens to that paper with your personal information if you get the job, dont get the job, etc. Is it discarded after a certain amount of time where the company no longer has your information or is it always kept on file forever. I recently applied for a volunteer opportunity and it asked for my social security number, I was reluctant to provide it because I do not want this personal information to fall on teh wrong eyes, I was worrying that if in the future I do lets say come into a lot of money that people in these organizations with my SSN and other personal info can access this info, I want to be safe, can I change my social security number and if so how?
What happen to job applications and other types of applications after time?
As a hiring manager of a small business I can tell you that if you DO get hired, it is legally required that your employer keep all personell records under lock and key with only authorized persons having access. If you do not get hired, there are two senerios:

1. if the company publically advertised the position, most states say you should keep the applications/resumes for 1 year.

2. They did not advertise then they can keep it or throw it away.

And yes %26quot;throw %26quot; away means in the trash. So your information could be at risk. Some employers need your SS# to run back ground checks and Credit checks, So you can always ask to provide that information apon request. That way you only give it out if you are seriously considered for the job.