Ghost Arm (really short fiction)

She woke up curled on her side as usual, eyes heavy and hair tangled. The light through the curtains was dim like early morning or a cloudy afternoon, time had no meaning in the stringy moments before movement and memory. At once she became aware of the arm beside her in bed, a long tube of flesh lying along the length of her body. Her own arm, she knew, must be beneath her: thhis was not her arm. Carefully she turned her head on the rumpled pillow to see who else was in her bed. Had there been someone there when she had gone to sleep? Had someone joined her in the night? As usual, there was no one lying beside her in the single bed.
Finally she prodded the arm with her hand, watching the finger indent in the still skin. She felt nothing. Grasping the limb and levering it upward, she found it attached to her shoulder and felt the terrifying weight as it flopped back down, numb and dead. At last a rational thought crept into her mind: this was going to hurt. She rolled on to her back in her empty bed and closed her eyes, hoping to fall asleep before the prickling pain set in.