I’m being left with the below lines after deleting attached objects, is there a way to remove these lines without selecting each one individually?
Any help appreciated!!
Lee
While I don’t see the exact issue from your image, you can click and drag the select cursor to open a window around multiple lines.
Drag left to right to create a solid window (only lines that are completely in the window will be selected) or right to left to open a dashed window (any items that the window crosses will be selected).
I also don’t understand the issue from your image, but I would guess that you may be using layers incorrectly.
The best option for a complete answer would be to upload your .skp file so we can have a look.
Thanks guys. I indeed was using components incorrectly! I exploded the component then deleted the objects which left the “lines”. If I made the objects I was deleting components then deleted them the lines were no longer there. Thanks anyway. 
If any other people has the issue: try using the “Wireframe” view, in the “Style” toolbar. If you can’t see the toolbar, go to “View” menu and then “Toolbars” (I’m using Sketchup Make).
With the Wireframe view you can see and delete those pesky lines. They also could be “invisible” to you because they’re the same color than the background.