\documentclass[a4paper]{article}
\usepackage{background}
\usepackage{lipsum}
\pagestyle{empty} % Disable page numbering

\newlength\mylen
\setlength\mylen{\dimexpr\paperwidth/40\relax}

\SetBgScale{1}
\SetBgAngle{0}
\SetBgColor{blue!30}
\SetBgContents{\tikz{\draw[step=\mylen] (-.5\paperwidth,-.5\paperheight) grid (.5\paperwidth,.5\paperheight);}}

\begin{document}
\newpage

\ % The empty page

\newpage

\end{document}
