I would be more concerned about eliminating the mouse. Can you put the fruit in the refrigerator?

Set a couple of traps and leave your fruit out.

Yep, set traps..... (peanut butter makes a good bait).

But is it fresh fruit or dried fruit? If fresh fruit, I would refrigerate it since it will be nothing more than a banquet-feast for a rodent. If it's dried fruit it can be stored either in the refrigerator/freezer or at room temperature in an air-tight container (like a canning jar or recycled commercial jar with a screw-top lid). Just don't vacuum-seal dried fruit with a FoodSaver and store it at room temperature because there is too much moisture in dried fruit to safely vacuum-seal it. Vacuum-sealed foods need to be 10% or less moisture content if storing at room temperature.

BTW - rodents can gnaw their way through plastic, if they are hungry enough. I tend to use canning jars for my pantry dry goods, but that's how I have my pantry designed since I use a lot of food items I vacuum-seal in jars with my FoodSaver (freeze-dried foods, beans/seeds/grains, dry pasta, etc.).

My shelves are just far enough apart that I can lay a canning jar on its side. I use all sizes of jars - as the amount in the jar goes down, I'll switch it to a smaller jar, but I can continue to use the lid if I choose all the same mouth-size of the jars. I lay the jar on its side and have the lid facing the front. Now that they are in a single layer, I don't have to shift several jars to get one out of the back of the shelf. I've actually increased the amount of storage I have using this method. No more "dead" space.

I use canning lids I have spray painted with chalkboard paint and write the contents of the jar on the lid using chalk pencils or liquid chalkboard markers. You can also write on the regular canning lids using the liquid chalkboard markers without painting them with chalkboard paint.

I kept wondering what are canning jars till I googled and realized it's mason jars which I also use. Thanks!

BTW, I can't keep fresh fruit directly in the fridge as many of them aren't fully ripe and interestingly, I don't see any marks on the fruits at all so does that mean mice aren't interested in them?

A canning jar is made out of molded tempered glass that can withstand heat processing and freezing. "Mason" was the first one (it's similar to calling a tissue a Kleenex). "Ball" is more common today, but there are other manufacturer's of canning jars.

Perhaps you are fortunate enough have your fruit placed on or in an area of the kitchen where the mouse hasn't been able to get to (yet). I would use a deep container with slippery sides for the fresh fruit to try to prevent them from climbing up the side.

I love that idea on how to keep fresh fruit - any links of names of these containers you've seen would help!

Did you just once see a few bits of "evidence" or is it something you see continually?
Mid summer is a very very strange time to have a mouse in the house....food is much more plentiful outside.

we've been seeing droppings every day for the last 2 weeks

Every year we get a mouse or 2, despite the fact that we have 2 cats. The cats usually let me know by their behavior that there is a mouse. Set some traps with peanut butter and you'll get it. But be aware, its usually not just one mouse, most of the time we find if there's one, there' usually another one (or 2)