Most of the tower footage in the film, both interior and exterior, were shot at the actual Tower of Terror attraction at the Disney's Hollywood Studios. (Then Disney MGM Studios)
Disney used this TV movie to test the waters of turning Disney Parks attractions into movies. What followed was Mission to Mars (2000), The Country Bears (2002), Pirates of the Caribbean: The Curse of the Black Pearl (2003), The Haunted Mansion (2003) and others. Only "Pirates" became a continued franchise.
Every time the hotel is seen from the outside, the Hollywood sign is seen behind it. In the 1939 sequence, the sign reads "Hollywoodland" which was the what the sign said back in those times.
The Sally Shine character looks are based on Shirley Temple who was a popular child star around that time