This is a quick how-to to clear out older files in a directory.

find /path/to/files/ -type f -mtime +7 -exec rm -rf {} \;

Explanation of the arguments:

find:	the command that will search for the files
/path/to/files/:	the top level directory to start searching
-type f:	so we don’t remove directories, only files
-mtime +7:	files older than ’7′ days. Change to ‘+14′ to delete files older than 2 weeks
-exec:	what to do with the files we find
rm -rf:	remove them recursively, force
{}:	this represents each file we find
\;:	the end of the exec

Now you can schedule this by adding a crontab entry to run every night at 2am:

0 2 * * * /bin/find /path/to/files/ -type f -mtime +7 -exec rm -rf {} \;