Don’t you have any scary decorations to put out tonight ? I might solve your problem.
Get a piece of paper (orange would be good but not necessary), a pen, a pair of scissors and some sellotape. Draw out a scary face, big or small enough to fit your outside light.
Stick to your outside light and you have your own scary Halloween decoration for tonight!
And get your pumkin tomorrow when it is really cheap and make all sorts of recipes with it.