Can you refinance a house that is listed for sale?

Yes, you can refinance a home that is listed for sale.

I, like many, have refinanced property/homes that are either for sale and even those with sale contracts on them.

Not only can you use the more normal types of finance, including lines of credit, etc., but the class (or term) for loans that are made exactly to do so is called "bridge loans" or "bridge financing". Generally because it bridges you from one to the other property. (If you are doing this to have the funds to close on a second property, you can sometimes arrange financing that essentially will cover both, with the first one dropping off at sale, called a blanket mortgage).

Understand, the mortgage company has nothing really at risk if you are selling, as their loan is secured to the property and they will get paid sale proceeds before you.

Contrary to the above, lenders (investors) would love everyone to pay off early! The interest rate you see (actually that thing called APR) is for the interest and costs over the term of the loan. If you pay a loan off early, you effectively pay a MUCH higher interest rate (actually APR). Much, much higher. Consider how much you would pay on say a 30 year loan you refinanced every year. Lots and lots of fees and up front interest, and at the end of 30 years, you wouldn't have paid any principal really and still owe the original amount! The early payoff of loans is one of the major income factors for lenders.