I need the title for something I saw on tv eons ago

I need help with name of tv movie--fromaround 1976...two freckled brothers (around 12 and 14 years of age) who are into super8 movies become amateur sleuths and investigatesome wrongdoings involving a Jacklyn Smith-like neighbour...I thinkit was part of The Wonderful Wolrd of Disney but Ihave failed to find clues. I recall everything being solved at the end and the older lady (around 25) they were infatued with being arrested.