input: from typing import List
  
  def generate_voltage_signal(freq: float, amplitude: float, duration: float) -> List[float]:
      """ Generate a voltage signal with random noise. The signal has a given
      frequency and amplitude, and the noise is normally distributed with a mean of 0 
      and a standard deviation of 0.1. The signal is generated over a specified duration.
      >>> generate_voltage_signal(250.0, 1.0, 1.0)
      [... ]  # Actual values will vary due to randomness
      """
output:     import numpy as np
      num_samples = int(duration * freq)
      time_points = np.linspace(0, duration, num_samples, endpoint=False)
      signal = amplitude * np.sin(2 * np.pi * freq * time_points)
      noise = np.random.normal(0, 0.1, num_samples)
      return list(signal + noise)