Water Leak Coming through wall behind Kitchen sink

[Leonard Smith]

Good Morning BP Family, About 3 days ago I started to notice standing water right around my kitchen sink. I thought it was just water left over from dishes but then it happened for the next 3 days. So last night I dried up water then waited to see if I can catch where the leak was coming from. I noticed the water was coming from what looks to be a small crack in the wall directly behind the sink. I then check under the sink and there was no water . Then I check the other bathrooms and HVAC and notice no leak as well. What might this be? Is this something I can easily fix myself or should I call a plumber. Should I put some sealant(I think that's what it's called) on the crack. Thanks Family