Can I use plastic wrap and make my own plastic wrap microwave ready potatoes at home ahead of time and store them like the already plastic wrapped ones at the grocery store?

Many retailers sell an over-wrapped potato as you describe, specifically marketed for microwaving – However, any potato can be microwaved. In fact, no plastic wrap is necessary. Simply rinse your potato(es), then pierce the skin a few times with a fork. Then, microwave until done (time will vary depending on the size and number of potatoes microwaved at the same time). Click HERE for a link to help.