It knocks at the front door..

[Roses Are Red]

Hi everyone,
So my mother tells me that lately something knocks at the front door .
Now in the past I had warned her that if she hears knocking and there's no one on the other side of the door not to open the door so she doesn't let any spirits in . As a result she doesn't open the door .

But at least once a month whenever I'm not home for whatever reason there's knocking at the door we don't know why or who it might be. Also when they knock and mom doesn't answer we think it goes around and looks into the house from the really giant patio windows because our dog keeps on looking at something like it's looking at something move around, we are on the second floor .

We don't know if it's grandma who passed away eight months ago .. I smudge the house regularly / but I do allow positive happy good spirits to stay.

Any thoughts of what's going on here ?