Yeah, I remembred you were lying in bed when you heard the door being fiddled with. But then you drifted back off. Possible you got up then, sleepwalking.

I don't sleepwalk, but I've done things in twilight sleep I have no memory of, usually talking. I've done things in my sleep on medication I have no memory of.

I used to have a pair of pets that individually could not open a locked door, but they were always in cahoots causing trouble. The cat provided the mechanical manipulation and the dog provided leverage and force. I wouldn't have left them in a car alone together for fear they'd take it for a spin like a little kid.

Even if your greyhound couldn't have opened the door, that could have been the noise.

If you have a ghostie, sounds to me like it's sad rather than malevolent. If you think it's the garage guy, you could try talking to him. Lots of times once they realize they're outside of time, they leave.

Hope the cameras catch something. Sounds like you and Mick are in for a bit of fun.