A sensing floor to locate people and devices is described. In an embodiment, the sensing floor (or sensing surface), is formed from a flexible substrate on which a number of distributed sensing elements and connections between sensing elements are formed in a conductive material. In an example, these elements and connections may be printed onto the flexible substrate. The sensing floor operates in one or more modes in order to detect people in proximity to the floor. In passive mode, the floor detects signals from the environment, such as electric hum, which are coupled into a sensing element when a person stands on the sensing element. In active mode, one sensing element transmits a signal which is detected in another sensing element when a person bridges those two elements. In hybrid mode, the floor switches between passive and active mode, for example, on detection of a person in passive mode.