What Do These Flowers Mean?

For around 4 years I have been finding fake, purple, flowers, with fabric petals and plastic stems placed into trees, outside of my windows, and right in the center of paths I have been walking. I can't seem to make a connection, but am looking into psychic readings as a form of spiritual guidance, and ultimately an answer to this strange phenomenon. From a very young age I have been able to sense the presence of spirits in rooms I have entered. My grandmother passed when I was 12 years old, and the night of her passing I could hear people entering my kitchen and moving the chairs in and out from under the table. The following morning I was sitting in my living room, and I had heard very loud commotion coming from in the kitchen, almost like a man and woman having a conversation, but it ended as soon as it came. I find that during the night once I wake from a deep sleep, I can see figures and sometimes fully developed images right in front of my eyes. At a young age, I recall waking up, and looking down the hall to see a young girl warming her hands over a nightlight that was in my hallway, as if it were a fire of some sort. This has only happened a handful of times, but each of those circumstances seem to stick with me and I feel like they could be of spiritual importance. Looking back I believe that spirits are sending me these flowers, and I am especially concerned with the possibility of this spirit being my grandmother, who I was very close with. I'm beginning to think that this could be an omen, but overall, I'd really like to know your input on my experience with finding these flowers.