I've had that mouse problem a couple of times. As an earlier poster noted, the comprehensive general liability portion of your auto insurance policy should cover the repair (but only one time, I suspect). I park my 2018 Sport outside. There are bushes nearby. I noticed that the chewing problem occurred during cold weather, when the mice sought out my under-hood for a warm place, and to bring food to eat. Then they discovered the tasty wiring.
Solutions that failed: all of the cat urine, smelly, chase-them-off-but-don't-kill-them ideas. Complete waste of my time.
First solution that kinda worked: I bought rat poison (the green blocks) from Home Depot - they are sold either by themselves or with a black-box bait trap - crushed the poison blocks into smaller chunks, then placed some of those chunks on sticky tape (or in cupcake paper baking cups, if you prefer) then taped/velcro'd the bait in 4 or 5 locations under the hood (they particularly liked the battery well). That seemed to work, BUT I had to remove the poison and clean the under-hood area each time I had anyone look under the hood. Not good - had to wear rubber gloves when installing/removing the poison for my personal protection.
So...place the bait under your Explorer's hood if you wish, but be prepared for frequent, messy removal/cleanup sessions.
So... second time, I trimmed back the bushes nearest to where I park my Explorer - I cleared away a 6" gap between the ground and the bottom bush limbs. Then I placed poison-baited rat stations under the bushes that were close by my Explorer. [These bait stations require the rodent to crawl into the bait station - this prevents cats, small dogs, etc. from getting to the bait.] BINGO.
So, my summary observation is this: find the place where these rodents normally nest, then find a way to terminate them in their own home, not yours. I haven't had rodent problems in 2 years, including the coldest winters in recent history.