Wis. Stat. § 893.44
A stock-purchase plan as a reward for increased profits is not subject to s. 893.21(5) [now this section]. Younger v. Rosenow Paper & Supply Co., 51 Wis. 2d 619, 188 N.W.2d 507 (1971). Professional services by a physician or attorney, although not customarily performed in the profession, may be classified as professional if requested by reason of the professional's expertise and training, if the professional then utilizes that knowledge and training. If the services are so classified depends upon the facts of the particular employment. Lorenz v. Dreske, 62 Wis. 2d 273, 214 N.W.2d 753 (1974). Section 893.21(5) [now this section] does not apply unless services are actually rendered. Yanta v. Montgomery Ward & Co., 66 Wis. 2d 53, 224 N.W.2d 389 (1974). If the object of a disputed contract is the end product or fruit of human labor rather than the labor per se, s. 893.19(3) [now s. 893.43] applies rather than s. 893.21(5) [now this section]. Rupp v. O'Connor, 81 Wis. 2d 436, 261 N.W.2d 815 (1978). An unjust enrichment claim accrues when a cohabitational relationship terminates. The court does not determine which statute of limitations, if any, applies. Watts (Bischoff) v. Watts, 152 Wis. 2d 370, 448 N.W.2d 292 (Ct. App. 1989). This section applies only to actions for wages already earned. Lovett v. Mt. Senario College, Inc., 154 Wis. 2d 831, 454 N.W.2d 356 (Ct. App. 1990). This section does not apply to actions for the recovery of sales commissions. Erdman v. Jovoco, Inc., 181 Wis. 2d 736, 512 N.W.2d 487 (1994). The distinguishing feature of personal services under this section is whether the human labor itself is sought and is the object of the compensation or whether the end-product of the service is purchased. Paulson v. Shapiro, 490 F.2d 1 (1973).