A provision in any written contract to settle by arbitration a controversy thereafter arising out of the contract, or out of the refusal to perform the whole or any part of the contract, or an agreement in writing between 2 or more persons to submit to arbitration any controversy existing between them at the time of the agreement to submit, shall be valid, irrevocable and enforceable except upon such grounds as exist at law or in equity for the revocation of any contract. This chapter shall not apply to contracts between employers and employees, or between employers and associations of employees, except as provided in s. 111.10, nor to agreements to arbitrate disputes under s. 292.63 (6s) or 230.44 (4) (bm).