My scooter is haunted

I bought it last September.

After servicing all fluids and new tires I started riding a few weeks ago.

I have my 650 Burgee in the garage by itself. I noticed something very unusual that made me think it is haunted.
It runs great and is a great ride. I placed air horns on it, a stereo system, a high rise seat backrest.

Anyway, I noticed when I get on my burgee, level it up and bring the kickstand up, engine off, ignition off, I hear a very faint high pitch moan like a little child crying. At first, I thought it was a kid playing with me outside of the garage. I even looked the first time it happened. Then it did it every time I got on her before starting.

I am thinking it might be the gas tank venting from moving.

Have you ever hear your scoot moan at you in the morning? I am thinking of naming her Casper with a decal on the side.