The hoses and valves at a washer box can remain under pressure between loads. Moisture while the washer sits idle can come from a supply valve or hose connection. Water that appears only as the washer pumps out points the plumber toward a different part of the box.
Find the first wet spot
Look at the visible valve outlets and the wall just below the box without pulling on hoses. Note whether water appears from the drain opening, a threaded connection, or behind the trim. If there is active leakage, stop using the washer and isolate the supply if you can safely operate the valves.
Explain what is accessible
Share a photo and mention whether the box is recessed, blocked by stacked equipment, or served by valves you cannot turn. A plumber can plan access and check whether the leak is confined to a connector or involves piping behind the wall.
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