If test - checking files older than 7 days - Unix

Question

I have created a script for my Synology NAS which checks the video folder to see if there are files older than seven days. However it is not deleting, the error message I am getting is

sh: of: unknown operand

Here is my script:

echo "------- SCRIPT START -------"
sleep 2

if test 'find /volume1/Media/ -mtime +7'
        then
                sleep 2
                echo "Deleting files"
                -exec rm -r {} \;
                sleep 2
                echo "Deleted files"
        else
                echo "There are no files to delete"
fi

Answer 1

a short script to just remove files older than 7 days:

dir="/volume1/Media"
days=7
echo -n "removing files in $dir that are older than $days days: "
find "$dir" -mtime +$days -type f -exec echo {} \; -exec rm {} \; | wc -l