Find files older (modified) than 10 days & remove them.

 

find . -mtime +10  -type f  -exec rm {} \;

 

Find files older than 10 days, file extension .log and remove them.

 

find . -mtime +10 -name'*.log' -type f  -exec rm {} \;

 

Find files older than 10 days, filename matching pattern (case insensitive) and remove them.

 

find . -mtime +10 -iname'*pattern*' -type f  -exec rm {} \;