Oven will not come on. My oven model number is whirlpool MH6159XMT-0. I read a leter from another

Question

My oven model number is whirlpool MH6159XMT-0. I read a leter from another person with a similar problem.When the start button is pushed, instead of hte oven, the exhaust comes on: it is an over the range type of oven. Nothing else comees on.In the other letter, I am referring to, dated Oct 24,206, you replied you repair something like this for about #32. My ZIP code is 60134. Can you tell me how I can get it repaired?Do you have any suggestion I can try? In the other reply, you said something about checking a door switch. Where can I find a door switch for this model?Thank you very much.