All you need is a damp-to-wet coffee filter placed over a bowl, plate or other dish:
Keep the microwave clean by covering food with coffee filters. It’s safer than using plastic wrap and keeps the splatters to a minimum. If I do get splatters, I put a wet filter in the microwave, turn it on for 15 seconds and then wipe the softened foodstuff off with the wet filter. Wait until the filter cools off a bit, first.
If some splatters manage to pass through your makeshift barrier, you can just use the filter to wipe them off.
25 Alternate Uses for Coffee Filters [Free Shipping]