Phantom limb phenomenon is explained by

The sensory fibres are experimentally stimulated anywhere in their course to the coex, the conscious sensation produced is referred to the loaction of the receptor. This principle is called the law of projection. Due to this, after amputation of a limb, sometimes patient complains of intense pain in the absent limb (phantom limb). These sensations are produced due to irritation of the damaged nociceptive and proprioceptive afferents at the stump of amputated limb. The sensations are evoked are projected to the area where receptors are used to be located. Ref: guyton and hall textbook of medical physiology 12 edition page number: 671,672,673