Ever since I moved into my house a few years ago this thing blinks either red or yellow at night. I can’t tell what it’s for. It’s connected to some wiring in my attic. Any ideas?

2. Security or Alarm System Components
Some home security systems include sensors, motion detectors, or control modules in less obvious locations, such as attics. These devices often use blinking lights to indicate connectivity status, power, or alerts. A red or yellow blink could be a normal indicator or might signify a tamper or wiring issue.

3. HVAC or Utility Monitoring Devices
Occasionally, HVAC systems, smart thermostats, or energy monitoring equipment installed in the attic have status lights. These lights can blink in patterns to indicate operation, faults, or communication with other devices in the house. If you have a newer system or energy monitoring setup, this could be the source.

4. Older Electrical Components
In older homes, you might find legacy equipment like surge protectors, power relays, or voltage monitors tucked in the attic. Some of these devices have LEDs to indicate activity or status. Red or yellow blinking could simply be a signal that the device is powered and functioning.