All of the patterns entered to match the various address fields are evaluated as case-insensitive regular expressions by default.
Address Alerts use POSIX Regular Expressions included in the PostgreSQL database engine. See the PostgreSQL documentation for full details.
If you want to do a case-sensitive match you need to prepend the pattern with "(?c)"
The simplest regular expression that acts as a wildcard is ".*", that matches any type of character zero or more times.