When you create a new ASP.NET project with membership it creates the default connection string for ApplicationServices as follows:
<add name="ApplicationServices"
connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|aspnetdb.mdf;User Instance=true"
providerName="System.Data.SqlClient" />
Is there a way to force this to use SqlServerCe in the App_Data folder instead of creating it in sql express?
no its not possible, but you can check it via code for data source..