seance

A Seance is when a group of people either sit around a table, or sit / stand in a circle.
They should link hands and not break the link whatever happens.
The linking helps unite their energy and the spirits can use this combined energy in order to communicate,
it also prevents suspicion of trickery by any of the sitters.
Ideally one person should be a medium or experienced psychic.
This person should invite spirit to come forward and communicate to the group.
Items such as bells, candles, mirrors etc are sometimes used as "props"... mirrors are often believed to be a portal into the spiritual realms, bells are often thought to bring spirit forward, and candles are often used as cleansing and communicating tools... the flame itself often tells of spiritual presence.
During a seance, spirit may use a number of ways to communicate, including

Ringing Bell
Rapping
Candle flickering / going out
Lights dimming / going out or switching on and off
Table Tipping
Orbs and/or spirit lights
Mist and/or Ectoplasm
Movement of items
Touch, Sound, Smell, Temperature changes, Taste
Clairvoyance
Clairaudience
Clairsentience
Symbolism
Trance
Transfiguration
Draught / Wind
Posession
Emotion

Spirit may communicate via the medium, but sometimes members of the group will also experience something or receive messages, so everyone should be encouraged to share what they feel comes from spirit, no matter how silly or insignificant it may seem to them, it could be an important message to someone else!
I personally have sat through three seances. These were performed by experienced psychics during
my first Paranormal Investigation at Craig Y Nos Castle in South Wales.
I experienced temperature changes, touch, smell, and also saw one unfortunate lady being posessed by a rather unwelcome spirit entity, who forced his way in through a hole he made in her aura. It later turned out she hadn`t properly prepared herself, didn`t know about Protection and so had left herself vulnerable to unwelcome attention. There are spirits out there looking for such an opportunity, and I can`t stress enough the importance of prayer and protection. Luckily for the lady involved an excellent medium, Andrew Garley
was nearby and able to come to her rescue.