Help Wanted: Kids
One of Disney's made-for-tv movies from the '80s. I think the synopsis from a Disney Wiki sums it up best:
When the Burkes lose their jobs in New York, they have to move to Arizona, where Tom has an job-offer in the management of a small company for children's clothing.
Unfortunately Tom's new boss Sirus Lovelin turns out to be extremely fond of the traditional American family and automatically assumes Amanda to be housewife and mother - but the Burkes don't even have children! To not offend him, they "hire" two kids they met prowling the streets. When they turn out witty, but nasty and impertinent, the Burkes want to rid themselves of them, but are entangled already too deeply in their lie...