A woman was woken by an intruder at her home in Hebden Bridge.
She went downstairs after hearing noises at the house at Foster Clough at around 11pm last night.
She confronted the man and he ran off empty-handed.
He was described as white, about 5ft 8ins tall, pale, of medium build and with a big nose.
He was in his late 40s to early 50s and was wearing a black hat pulled down over his ears, a black jacket that came down to his hips and was carrying a torch.
Anyone with information about the incident or who saw anyone in the area acting suspiciously should call Calderdale CID on 101.