Variables class with ConnectionStrings

[Darkmatter5]

I have 4 connection string, 1 for LocalDB, MySQL, SQL and SQLite. I also have a variables class, I want to be able to pull the connection strings from the applications local settings and use the DbConnectionStringBuilder to get specific data from those connection strings and store them in different variables that I can use in other places/classes of my application. I'm still trying to learn class usage, so this might be really jumping the gun in my learning process. If you can suggest a better structure on how I should do this please let me know.

Here's what I have so far.

public class variables
{
    private static System.Data.Common.DbConnectionStringBuilder bldrLocalDB = new System.Data.Common.DbConnectionStringBuilder();

    public static System.Data.Common.DbConnectionStringBuilder dbcsbLocalDB
    {
        get { return dbcsbLocalDB.ConnectionString.ToString(); }
        set { dbcsbLocalDB.ConnectionString = Properties.Settings.Default.csLocalDB; }
    }
    public static string csLocalDB
    {
        get { return bldrLocalDB.ToString(); }
    }
    public static string dsLocalDB
    {
        get { return bldrLocalDB["Data Source"].ToString(); }
    }
    public static string dbLocalDB
    {
        get { return bldrLocalDB["Initial Catalog"].ToString(); }
    }
    public static string unLocalDB
    {
        get { return bldrLocalDB["User ID"].ToString(); }
    }
    public static string pwLocalDB
    {
        get { return bldrLocalDB["Password"].ToString(); }
    }
}

Currently the line "get { return dbcsbLocalDB.ConnectionString.ToString(); }" gives me the error "Cannot implicitly convert type 'string' to 'System.Data.Common.DbConnectionStringBuilder'".

Am I even going about this in the right way?

Thanks!