Most common forms of paranormal activity
The most common forms of paranormal activity do not always involve spirits or demons but may be energies. There are considerations which are non-paranormal causes for these activities as well.
Lights turn off and on, or flicker, without affecting other electronics and with the absence of power issues such as surges or outages. Wiring, circuits, and fuses/power boxes can deteriorate causing similar behavior.
Electronics, typically television or radio change changes or power on/off by themselves. Occurrence have increased with the advent of universal controls and mass manufactured products which use the same frequencies.
Items are not where you left them, plate stacking, book stacking, keys missing, etc. Sometimes you may perform an action out of reflex and not register in memory or other members of the household may have acted and you are unaware.
Vehicle or device
A vehicle or device will not start with no apparent technical problem but then when attempted later will operate normally. This intermittent behavior can also be the result of a short in electronics or a relay not working properly.
Opening and closing
Doors open and/or close without the presence of wind, movement, or temperature change. Homes may settle, or an action in one part of a home causes a reaction in another part (Opening front door results in pressure change closing bedroom door without a detectable presence of wind).
Voices and sounds
One may hear whispers, a single word, a voice in the white noise of electronic devices. One recommendation is to record audio. Often when the recording is played back voices and sounds are much more prominent such as a word, phrase, footsteps, etc. There are devices the operate on close frequencies and can bleed audio into others such as some older blue tooth, wifi, and IR devices.
Animals seemingly stop and stare or run away from something when there appears to be nothing. Hissing or barking as if a presence only visible to their eyes. Animals have personalities and may simply be acting playful.
A significant increase or drop in temperature, sometimes in a very isolated spot or portion of a room, or the entire room, while the rest of the area appears to be unaffected. Broken or inefficient temperature control (heater/air conditioner/duct work) may affect this.