Seeing a white presence

Hi, this is really random now. My nephew passed away 4 months ago. We’ve had signs, smells of cannabis in my house as he used to smoke it, feeling taps on my legs at night. Today I was sat on the sofa and in the corner of my eye I saw a white figure move past the window in my garden, I sat up panicking and watched with my own eyeballs a white figure walk past my back door, walk past the dining room window and around the corner of my house. I jumped up in panic and ran to the back door to make sure it was locked as I thought someone had broke into my back garden. This figure was just pure white, it didn’t look like a person, it looked like a person had a white sheet over them. Can someone tell me if this was a spirit? Could it have been my nephew? My whole body went want and fuzzy, I recognise the feeling of warmth when I’ve felt my nephew around but what I saw I saw, I saw this with my own eyeballs, not in the corner of my eye, like straight looking at it.