BE-58 general aviation pilot reported an engine failure during cruise flight. The pilot diverted to an alternate airport and landed safely.

Narrative

Returning to ZZZ from dropping passengers off at ZZZ1. In cruise; roughly 40 minutes from ZZZ; the right engine seemed to fade away. I started yawing; and slowing down; and recognized the symptoms of losing an engine. Since I was at 8000 feet; I had time to assess the situation. Looking around; I attempted to troubleshoot the problem; both enrichening the mixture; and putting the prop full forward. I identified the dead engine; and asked Center for the nearest airport. I received a vector to ZZZ2; turned toward it as I stabilized the dead engine; feathering the prop and followed the procedures to shut down the engine and prepare for a single engine landing. After listening to the ATIS; and stabilizing the aircraft; I planned for a high right downwind for Runway XX. As I made the left downwind for XX; I loaded the RNAV approach to ensure that I was approaching the airport safely; with the intent that I would be best set up for a controlled single engine landing; and would only need a go around if absolutely necessary. With the right engine feathered and shut down; I made a successful landing; and once shut down; I called our company maintenance and worked through the problem. They drove up to investigate the problem/cause. What was found was that in adjusting myself in the seat; I inadvertently kicked the right fuel selector just out of the 'on' position; hence the feeling that the engine just faded away with a low oil pressure indication as fuel flow was cut off to the right engine. Director of Maintenance and I discussed the cause; results; and how to remedy how to prevent this from happening in the future. My decision to land immediately was predicated on the terrain around me. With little to no options for off-airport landings; I felt it was prudent to not spend time in the air troubleshooting; in case the conditions worsened.