Etiquette in asking for funding proposal example I'm a postdoc and I have never submitted a research proposal. 

There is a funding project at my current University open to postdocs. I have a list of past winners and I'm tempted to ask for their proposals to give me some guidelines in writing mine. Obviously I can just ask and I know that professors share winning proposals, but usually, they know each other. But I've never met these people and the only thing I have is their contact information. 

What is the correct way to ask for sample proposals and is it considered good manners to ask such a thing?
First: Good approach to looking at successful proposals first. You cannot write a winning proposal if you don't know how winning proposals look like.

Second: Most people will probably be loath to share their proposals with anyone they don't know. But at the same time, most professors will (or at least should!) share their proposals with those they mentor in one way or the other. In fact, they may also take the time to walk you through the process, look over your proposal, give you feedback, etc. So ask your superiors, your department head, or others in similar position who look after your career development to help you with proposals that have been funded.