Paranormal experiences that are based in physical senses are difficult to pin down. I personally believe that sensitive people often don't know they're sensitive because they experience a lot of these small and simple touches from beyond, but the sensations are lost in the flood of everyday sensation. Touches, sounds, or visual evidences are also the first to get targeted for debunking. Rightly so, after all, if someone is looking for ghosts, then they make themselves hypersensitive to the environment and subconsciously attribute any number of small normal things to the paranormal.
In the past couple of months, I've had some physical experiences that are very unusual for me. Some weeks ago, I was in my kitchen at home cooking a meal when I felt my dog walk by my leg and touch her nose to my calf. She does this on a regular basis. It's like a habit, her way of saying, "Hey, just passing through." She does it when I let her in the house from the backyard, like tipping the doorman. It's just a little touch; just enough to give you a little wet spot that evaporates before you can wipe it off. Dog boogers are gross, but the intent seems nice enough.
Anyway, that evening I felt her do it and turned around to give her a piece of what I was cooking. I was shocked to see she wasn't there. My dog can move through a room pretty fast, and she's really quiet, so I asked my mom if my dog had walked through the kitchen. No big deal, until mom said my puppy had been asleep at her feet for an hour and was still there.
It's very hard to mistake a touch that you've had for years, consistently, under the same circumstances. I don't know of many things that could replicate it, especially at the exact ground level of my poodle/terrier mix. We did have a dog before this one who was exactly the same size, and had the same habit, but she only did it when she wanted food. Unfortunately, we put our old dog down 8 years ago after she broke her hip.
Maybe she just popped home for some griddle steak?
** I want to add this as an addendum. I had some difficulty posting this nearer to when it happened, and it's been a couple of weeks. These touches have been occurring occasionally since then with the same completely unknown source. Each time the dog has been out of the room or even outside the house. I've also experienced what felt like a hand patting my shoulder when I'm alone in my bedroom. Not a negative touch, but I'm more used to empathic experiences... Not physical ones.
Sounds like she is saying Hi to you.