The competition; really?
You think you are in competition with the house down the block?
When I do an Open House, I invite the Realtors from proximate Listing to hold one at the same time!
Is this keeping your enemies closer?
If I had to rely only on myself, to sell all my own listings; I would be in trouble.
Other Realtors are not my enemies.
Also, when I'm getting ready to show some houses, I always pre-view them: I want to know everything I can about the competition.
Did this guy disguise himself to look like a Realtor?
Or, perhaps, as others have suggested, he was "previewing" the property. Maybe he told the person he made the appointment with, that he was previewing the property... or maybe he forgot. Either way, it was good that you cleaned the place for the viewing, as a preview from an agent is every bit a "showing" as a regular showing with a client.
If you'd known it was just an agent... would you have left the laundry on the laundry room floor, or dishes in the sink? I know that being on the market is hard work, and can be frustrating. But this is part of being on the market.
What can you do? You can have your agent call the agent and thank him for previewing your property.
Here in Seattle, when we call to tell a seller we're planning a visit, we inform them as to whether it's a preview (just the agent) or a showing (with a client).
In either event, we recommend to our sellers that the home look fabulous, because that first impression is the lasting impression, and we remind them that many visits will be from agents that have competing listings - but those agents may wind up selling the home, because they may get calls from buyers who don't like their listing and may be interested in others in the neighborhood.
So what you "can do about it" is to roll with it, and appreciate that at least someone is interested in your property. It will sell soon, if it's priced well enough.
All the best,
Perhaps, as a courtesy, he should have said he was "previewing the home", and told you he wasn't bringing a buyer with him............but..........he wasn't "snooping" - he was doing his job - staying on top of the local market....especially his listing's "competition".
Besides - maybe in the future he will have a buyer for your home..........someone who doesn't like his listing.....now he can show yours!
I hope your agent has seen, and continues to preview, all the houses that are competing with your home, too!