Acting crazy after getting wet

My phone went for a short spin in the washing machine a few weeks ago. After drying out it came back to life with the usual screen issues. I began to use it for a few days but them in the middle of the night Siri came on and started talking. The screen was moving from Siri to search and back as if I was tapping the home button over and over. I have tried resests, soft and hard etc. This problem is intermittent but consistent.

First I thought it was a bad home button cable but that has been replaced. I should have known it wasn't a bad home button cable since the problem persists when the case is open and the home button has no contact.

Anyone know what can trigger the home button when it's not connected? I have not completely cleans the phone yet after the water issue. I was hoping to get a bit more specific on what parts could cause the above symptom.