Thanks for all the info! I am convinced this is indeed is an electric in line fuel pump. From the descriptions and pictures that is the only thing that matches exactly. But it does not run... no clicking noise or vibrating when engine is turned on or running, so must have been for some other purpose, backup, temporary stand in while original pump being repaired, who knows. Not sure it would ever have been used for bleading lines as the engine comes with an electric in line pump so why add a second one?
I am probably going to test it and remove it if it doesn't work. If it does may leave it as back up.
To answer some other suggestions it is definately on the fuel pick up line from tank to filters to engine. That was easily traced. There are no other gauges, alarms or holes in dash that would suggest this was a working sensor, although because I thought it was not THE fuel pump I was thinking it might have been a sensor of some type.
Again, thanks!