How many are you hosting for ?
Hallowe'en Games :
Things in a box - they put their hand in to feel .
Mashed potatoe , wizened carrots with rice crispies glued on, cold spagehetti ......and the last one your hand 
Eating jellly without using your hands . Small jelley on a paper plate , dig in
Donoughts on a string , no hands
99p dolls pull the legs/arms/hands off , put in soapy water in a bucket and you find the body parts and re-assemble
Turn Daddy into a Mummy . Wrap someone in looroll fastest time wins . No bodypart left uncovered . We got a family member to wrap round the bum or the "Mummy" does that bit themselves first .
Get some music downloaded and some witches /monster laughing
LED candles in jars , wrapped in coloured tissue paper to make safe lamps
We changed the lampshades for one of those big paper ones covered in coloured tissue or you could get a colour change bulb
One year I decorated the front room with 'scene setters' ( creepy forest or similar) and the toilet with bloody handprints stickers
Decorate out the front
Pumpkins ,
Glo sticks pushed into loo roll tubes with 'eyes'cut out , hide in bushes
Giant spider in webbing
A film (short one) to calm them down a bit
What food are you having ?