Why does my oven light flicker when I close the bottom drawer?
There are two switches and they are in parallel--a door plunger switch which closes when the door is open and a lever switch which is manually operated. The switches are connected so that if either switch is closed then the light goes on.

Is the flickering occurring with the oven door closed? Is the console switch on or off when the flickering occurs?  

Possibly only one is bad (and most likely it is the door switch), but first check the operation of each switch manually and see if you can get any indication.
The door switch is closed when the oven door is opened. The manual switch will be on the console.