You can get the same thing with the switched-mode (chopper) power supply found in many modern TV sets when fed severely under-voltage. There's enough juice to charge the reservoir capacitor, the start circuit will try to get the oscillator going, but as soon as it draws current the voltage drops too low on the capacitor, so it drops out again, then the whole cycle repeats.

The typical results is a regular flashing of a power/standby light, sometimes accompanied by a regular "ticking" sound, etc.