Here's how you can get a postcard sent to your child:
Write a letter to your favorite Disney character (it's not just princesses, you know!). Be sure to include a return address!
Send the letter to:
Walt Disney World Communications
P.O. Box 10040
Lake Buena Vista, FL 32830-0040
Walt Disney Company
Attn: Fan Mail Department
500 South Buena Vista Street
Burbank, CA 91521
Wait about 4 weeks and your child should receive their card in the mail.