Lower oven intermittant operation-cleaning

Diagnosis is the important aspect. Ovens have plunger-type switches to tell the "brain" door is closed, both for the light AND to allow initiation of self cleaning. Finally discovered one of those switches was "scratchy" in operation and unreliable in closing the circuit. (Push the plungers in and out several times and observe the light.) If not 100% reliable, replace that switch (cheap and easy with a Phillips screwdriver.) Initial guess was a $major "brain"-electronics problem but it was merely a sticky switch. Strange since the unit is about a year and a half old and rarely used. Found the part easily with PartSelect, and it came via UPS quickly.